heh, im not so much a hater as everyone, i do think mario is a good character, maybe not the best but i have a few reasons y hes good
1) most people dont know how to play him, dont know his move sets so thats always an advantage
2) i generally get a lot of cheap kills bc of cape and edgeguarding, theres nothing wrong with throwing a fox, falco off the edge at like 12% ( back throw ofcourse)
3) hes a great stock holder, if u play him right
i always feel in these situations u need to play careful.....no running in Die Hard style, make them come to u.....
most of the time who come at u will come with a move with high priority, fox/falco d-air, marth ranging attack with sword (any move haha), i generally play safe and either rush him with a n-air, d-air, or ill wavedash away and f-smash.....its a cheap strategy but it works!! so u dont take damage and u dont lose many lives, which is vital for teams
helping ur partner is always key, when they are about to edge hogged, i come in with a running f-air usually, or a wd forward d-smash to get them off the edge, if i f-air, most of the time they arent paying attention so they get spiked, d-smash is great to get them off the edge as well
also for stock survival, i generally get back if i have all my recovery options (tornado, cape, bl jump) so if i generally always call to my partner if im off, and a good partner will make sure the edge is free for u to get back, which is prob the hardest part for mario in recovering, getting ledge or dealing with lag when up- b on top
if u break it down like maelstrom does, i agree mario looks awful, but those things ive always dealt with as mario in singles as well, i always find the trick to playing mario has always use ur brain, figure out whats how hes going to attack and counter attack with either, rushing him b4 he attacks (c.falcon d-air), using a higher priority move (mario doesnt have many but d-air, u-air in some cases, wd back f-smash) or if u can sheild grab and start comboing.........
its a lot harder to combo in teams, i agree, but if u keep an eye out for the other opponent, most teams fights end up being 1v1s seprate, so if u just keep an eye out, or listen for the person to scream out, enf with a d-smash or f-smash earlier than usual, its not that big of a deal, or throw ur opponent into his teamate or towards ur teamate and let him kno to do a team combo
i genereally do decent in teams in tourneys....so i dont think hes like a total loss to pick like some people say, i have a decent marth but i still think my mario is better in teams
theres my 2 cents about teams, i try to cover everything but i prob left out something haha, hope that helped