Pichu exploits all three of these qualities where being fast fallers makes it easier for them to be comboed by Pichu and Pichu's ability to edgeguard is also good considering it has high active frames for its Nair, Fair, and Bair and Fire Fox's and Fire Bird's slow launch frame makes it easier for Pichu to spike Fox and Falco with Dair. Fire Fox travels the furthest letting Fox recover from farther away than Falco and Wolf, but it also means the further away he is, the more time Pichu has time to plan how to counter Fire Fox. What doesn't help is the increased startup on Fox Illusion. It always had higher startup since at least Brawl at 21 frames, but Ultimate increased it to 25 frames because apparently not being able to pass through shields wasn't enough. It does have the lowest recovery on the ground compared to Falco Phantasm since it has the same total frames as Falco Phantasm on the ground, but in the air when Fox wants to use it to recover, it being 6-7 frames slower on startup compared to Falco Phantasm and Wolf Flash is a problem. If you're only considering them as burst movement options, Fox Illusion has 31 recovery frames on the ground and 48 in the air with 16 landing frames, Falco Phantasm has 38 on the ground and 49 in the air with 16 landing frames, and Wolf Flash has 29 landing frames since he enters free fall regardless of where you use it due to it moving up at an angle.
Falco, therefore, has a fast horizontal recovery and one that can spike airborne opponents, but Fire Bird is strictly worse than Fire Fox and arguably Fire Wolf. It has shorter travel than Fire Fox, but has the same launch frame where Fire Fox's launch frame can kill. It travels further than Fire Wolf, but Falco might have preferred a faster launching Up Special even if it had shorter travel.
Wolf's Fire Wolf and Wolf Flash have the fastest launch times at around frame 19, so it's easier for Wolf to mixup his recovery unlike Fox and Falco where you know if they do their Up Special, it's going to be much slower than their Side Special. Fire Wolf and Wolf Flash are also very threatening moves as Fire Wolf trades charging hits and distance for knockback and sweetspotted Wolf Flash will kill where Wolf can choose to Wolf Flash onto the stage instead of to the ledge. The only problem is that Wolf Flash leaves Wolf in freefall, Fire Wolf has the shortest travel, and Wolf's low jump height means its easier for Pichu to gimp Wolf than the others.
All three of them also don't really do well against small characters since except for Wolf who has his Fair, none of them have aerials that arc or cover well in front and/or below them. On the ground, however, all of them can angle their Ftilts, Fox has reverse Utilt, Falco and Wolf have Utilt, Fox's and Falco's Side Smashes have arcing hitboxes, and all three have Up Smashes that cover well in front of them. That said, their range is limited to how far their limbs can reach and that's usually going to be shorter than someone like the Pits, Marth, or Triple D who use weapons or Bowser, DK, and Ridley who are big characters.
Fox has the advantages of his ground speed letting him outpace or keep up with Pichu and having the strongest and possibly the most reliable kill confirms that were carried over from Smash 4. If Fox can land Nair, Dair, or whatever into Up Smash, he probably would have the easiest time killing out of the three. Up Smash out of shield is also another good option, but also the riskiest one since his has the highest recovery at 45 frames for how long its active, clean and late hit, or 49 if you're only considering the earliest it can hit on frame 8. Falco's has 32 recovery frames for how long its active or 43 for its earliest hit on frame 7 and Wolf's has 25 recovery frames or 35 for its earliest hit on frame 13. For his disadvantages, Fox is the lightest and his range is probably shorter than Falco's and Wolf's. Also, Fox's Blaster lasers don't have knockback, so it can be harder for him to keep Pichu out by trying to zone Pichu.
Trading isn't something Fox should be doing even against Pichu, the lightest character in the game. Pichu is a glass cannon and Pichu's aerials look like they have higher overall kill power than Fox's where Pichu's Fair and Bair have high active frames, Pichu's Nair probably can kill off-stage, and Dair is a spike that also has a setup into it. On the ground, people will have to deal with Pichu's derpy Ftilt of doom -- maybe we should call it the stanky leg -- and its Smashes where Side Smash is a disjoint, Up Smash has ear invincibility, and apparently its Down Smash also makes it invulnerable 1 frame before its startup and 1 frame before its second hit, frames 7-10 where Down Smash is frame 8 on startup. Anyway, trading is what kept happening in Winners Finals between Larry's Fox against Void's Pichu. Both of them were going to die regardless, but it seems like Pichu has the advantage in being able to kill Fox at similar or earlier percents.
Falco has high active frames on several of his moves, dash attack, Utilt, Up Smash, Nair, Fair, Bair, and Dair letting him catch or still be able to damage his opponent when Fox and Wolf cannot, especially off stage allowing Falco to edgeguard fairly easier than Fox and Wolf. Although, when it comes to edgeguarding, I feel like Pichu might have the advantage over Falco here. It doesn't mean Falco can't edgeguard Pichu, but Pichu would be able to edgeguard Falco just as easily as with Fox and Wolf. Falco's also the only one out the three to have or still retain invincibility for his Up Smash giving him a safe anti-air in addition to his faster anti-airs, angled up Ftilt and Utilt. Falco's air to air capabilities are also pretty good with Nair and Fair. Up Smash out of shield is also good as Larry demonstrated with both Falco and Fox, but Falco's Up Smash is weaker than Fox's -- not sure compared to Wolf's. Like Fox, his Dtilt is also a natural disjoint since it uses his tail, but it's not disjointed like Smash 4 and it's no longer the frame 7 tail sweep it used to be in the previous games making it not as fast of a poke or punish. His drawbacks are that he's only really mobile when it comes to moving vertically as other than his walk speed, his run and air speed are below-average and his dash is now average in Ultimate. Pichu isn't that fast, like Little Mac fast compared to Falco, but Falco will have a harder time chasing after or avoiding Pichu whether it's on the ground or in the air compared to Fox and Wolf. It's his vertical mobility, however, that when combined with how his moves launch his opponents that Falco is able to follow up from a variety of moves letting him pile on damage against an opponent who isn't able to react appropriately or DI correctly. Falco does have kill confirms, but they're a bit weird and not as reliable compared to Fox who you just want to land Nair or Dair to be able to confirm an Up Smash while Falco needs to land with the loop hits of Nair or Fair and avoid Fair's landing hit to confirm his Up Smash. There's also the issue of Fox's Up Smash's horizontal range being longer than Falco's both in actual range and Fox being able to run a fair distance and catch an opponent with Up Smash.
I feel like Wolf's moves would let him do well against Pichu, but Wolf's recovery is what would kill him and as far as we know, Wolf's lack of kill confirms would make it harder for Wolf to kill Pichu in any other way than landing moves raw even if his kill moves have a lot of power and Wolf is the only one of the three to have a reliable kill throw. Wolf would have an easier time hitting Pichu with his aerials, namely Fair and Nair, his Blaster combined with his high overall mobility would let him control space, and he's no slouch on the ground either, so overall, Wolf could probably safely poke away and build damage on Pichu. It's in those crucial moments, when Wolf needs to land a kill move and when Wolf's off stage and in disadvantage, where Wolf will struggle. Regardless, all three cannot make mistakes as easily against Pichu. The other thing is that Wolf might have a harder time juggling Pichu since even though his Uair is good, Wolf doesn't jump that high nor is he a speedster on the ground like Fox and his Uair isn't a Chrom, Cloud, Ike, or Cloud Uair that has a lot of range. With regards to the player, I don't know how much Larry has played Wolf to be comfortable enough to challenge VoiD who's been labbing Pichu for all this time. That's probably why he didn't choose Wolf, but instead opted for Falco instead.
And then there's Luigi. He is not a fast faller, so he could escape being comboed more easily and his Nair is frame 3 where if it's anywhere near as powerful as it was in Smash 4 could probably kill an overconfident Pichu and for all intents and purposes, Luigi has two reversals through his Super Jump Punch and Luigi Cyclone. SJP is invincible on frames 8-10 on the ground and frames 6-8 in the air. A very poor shield approach from anyone could lead to a severe punish from Luigi, but it's risky, it has 45 landing frames and sourspotting it the worst thing you could do with it, so it's not as reliable as Doc, Mario, the shotos, and other characters doing their dragon punch Up Specials out of shield. In return for losing another vertical recovery option and powerful gimp and finisher, Luigi Cyclone gained invincibility on frames 4-8 on the ground and frames 1-7 in the air. I don't know how well a Cyclone out of shield would work, but if its reliable enough, then Luigi has these two moves on top of Up Smash, Nair, whatever as his out of shield options. These traits would help him in addition to having good normals and having a projectile to control space, but Luigi suffers from same recovery problem as the Star Fox characters where Luigi's issue is his very low air speed, lack of a wall jump to help out, and slow horizontal recovery move rather than falling too fast and/or having too low of a jump, Luigi isn't fast on the ground or in the air which could lead to Pichu overrunning him, and of course, Luigi having a tether grab has both its advantages, its range and being able to act as another aerial option, and disadvantages, the slower startup.
So, with character picks, I feel like Larry didn't have anyone else, but Fox and Falco as characters he was comfortable enough to play at that high of a level. For me, I feel like characters who outrange and can safely hit Pichu would be good counterpicks. In particular, Lucina, Marth, Meta Knight, toon and young Link, the Pits, and possibly Shulk come to mind. They're all fairly fast characters in movement and frame data where the Links and the Pits would be able to zone as well. Shulk's in that weird spot where through Monado Arts, he is able to alter his stats, so he can be fast or hit harder when needed, but it's iffy. Chrom, Cloud, and Roy also work, but their recoveries are exploitable, so you would need to be on point with them or else risk being gimped constantly. Robin being slow is a problem, but if Robin can keep Pichu out, then it should be fine or not and Robin will just get smothered to death. Ike and adult Link on the other hand can take hits well. Not sure about Corrin or the Belmonts, however. With regards to heavyweights, Bowser, DK who Larry did play in Smash 4, and Ridley might work, but they're big dudes making them walking punching bags for Pichu. Bowser and DK have invincibility on several of their normals and all three are mobile on the ground or in the air.
discussion a bit. Brawl vets are def gonna have an easier time playing him and figuring him out while fighting him, but I ALSO think Brawl Snake players also have to adapt to the new stuff that Snake has in this game, namely new Nikita which is starting to see wide use, but ALSO how much his ground and air game are fundamentally different.
