i don't edgeguard with ivysaur like...at all lol. my bad. i think bair would be effective though...
most of the matches under 3 minutes were of me winning at the beginning.

but there are a few of you two stocking too so i'll send those to retro.
the thing is that the over 3 minute matches were the best, those were more even.
squirtle was really effective at the beginning, but i never changed up my tactics so when dan figured it out, squirtle kinda lost its luster. you can hardly shellshift against olimar, his grab range means you won't get close without risking it, so if you stay far away, you aren't really going to be accomplishing much.
squirtle's dair will eat through any vulnerable pikmin and continue to hit olimar. if oli shields, try to land behind him so you aren't vulnerable.
dair is an amazing gimper on olimar, it sends oli at a shallow horizontal trajectory downward. if the last hit connects on olimar and he's at the edge of the stage, olimar will likely die.
charizard's fair does an amazing job at gimping olimar.
if zard has a good grab game, then he can easily rack up damage by mixing in some grab released jabs, and possibly another grab after that. zard's fthrow and bthrow are terrific at getting olimar off stage, setting up a gimp. zard's grab game is extremely important in this matchup. it's the single most effective way of getting olimar off stage.
you may say "but olimar's grab range is superior so good luck getting that grab in!" a valid response! charizard can't usually just dash in and grab olimar, oli can just fsmash you or grab before you reach him. use some sh flamethrower, use (a lot) of rock smash, sh bair at olimar a bit. rock smash is a good lead into a grab, and it's not terribly difficult to land. it'll kill or knock away any vulnerable pikmin in the vicinity and the shards will likely hit olimar, at which point zard can try and grab oli and have some fun! if olimar is busy doing anything that isn't a grab, zard can shieldgrab and get ahold of olimar.
any time charizard hits olimar or he's above the ground in the air, charizard has the option of dashing in for the grab. zard's dashgrab is VERY effective, please don't underestimate it. zard has an amazing combination of dash speed and grab range.
also, dsmash is a very nice punisher against olimar, assuming the start up lag doesn't bite zard in the ***. it'll kill vulnerable pikmin standing on the ground. the most effective use is after shielding oli's own dsmash. if the olimar rolls a lot (dan didn't, really) then dsmash is also pretty effective there too.
i agree with most everything dan said concerning ivysaur. and i also thank him for thinking my ivysaur is good. :D one thing that i didn't do with ivysaur was use bair. like at all. i'd use it maybe a few times per match really. but i think it has its uses against olimar. for one it can be pretty effective off stage, but as i said, i don't try to gimp with ivysaur at all haha. second, it can be an effective mid ranged approach. i'm pretty sure it'll hit away any pikmin oli throws at you and its range makes it difficult to punish. as dan said, it's lagless so ivy can follow up with an ftilt or something...following up with a leaf or two could also be an effective spacer.
also ivy's usmash is THE most powerful usmash in the game. ivy's fsmash has surprisingly amazing range. ivy's fair will kill oli off the top at about...eh maybe 110-120%. uair will kill at like 75%, maybe a tad lower. fsmash usually hit dan into a pretty horizontal trajectory, and at that point ivy can just tether onto the ledge to gimp. usmash will kill at like 50% lol. but anyway, ivy just has to keep spacing and poking and prodding until it gets the opening it needs to kill. fair is a more effective killer than i thought, and ivy should be using bair to space anyway.