You call us out on disregarding Mario; yet you still need to understand what GW can do as well. He has massive disjointed hitboxes; Mario's worst nightmare (see: Marth). He has brute force smashes with IASA frames that will obliterate Mario at low enough percents despite him being a middleweight. GW's aerial game without question outclasses Mario's.
Marth is not bad at all for Mario. The matchup is no worse than 6/4 Marth, contrary to what the Marth boards say. Marth's attacks can be punished out of shield, and Mario can force the approach with fireballs to an extent. Mario also has tools that mess up Marth's recovery a lot. If Marth whiffs ANY kill move on Mario, he gets stutter step F-smashed.
Believe me, I used to be the first person to think G&W was Mario's worst matchup. And yes, G&W's superior Smashes are a huge chore for Mario to work around. The really good Mario players however can time the F-smash perfectly to outspace you on most of your ground attacks.
How is Mario supposed to answer GW's Up B? If Mario does catch GW by Down Bing his Bair, GW will Up B out of danger before he gets nailed by a Usmash or Up B. GW's Up B has invincibility frames as well, and it also has a vortex hitbox for blowing you away or sucking you into the attack.
Nobody really has any good answer to G&W's Up-B. =/
As you're coming down though, if the Mario is good at chasing you down, he can get under you, and if you try to attack his shield, he can then Up-B OOS and punish you reliably. If you're at a kill percent, replace Up-B with Up-smash.
If Mario ever gets inside of GW's zoning, GW can simply Up B OoS and reset the situation.
Mario's Jab = 2 frames
Mario's Up-B = 3 frames
G&W's Up-B = 10 frames
It's not THAT simple. =/
GW doesn't even need to bucket fireballs. He can just block them with Dtilt, get out of a sticky situation with an Up B, or steamroll through them with moves like Bair.
Unlike Luigi, Mario's fireballs can be angled by gravity. Meaning you can't just sit in one location idly fanning away his projectiles.
Against most good Mario players, I don't Bucket at all in this matchup. The good ones always wait for me to have an attack out and then try to hit me with a fireball. Yeah, it's not the most threatening thing ever, but if you mess up at the wrong time, Mario has more speed and can hit you before you can hit him back.
GW does what he does very well... and that is thrash low tier characters.
I can agree with 65/35 G&W. But it's not an extremely hard counter like some.
Also, good Ganondorfs are really devastating. They can answer your range, they can combo you a lot, and KO you at ridiculously low percents. If there is one low tier that gives G&W a lot of trouble, I'm convinced it is Ganondorf.