I was wondering if there could be some type of deterrent for pikmin spammers. As of now there's nothing to prevent someone from adopting the play style of just run away and keep throwing pikmin. Maybe Olimar could receive slight damage if the pikmin are knocked off before a certain amount of time. I don't know. I just don't like it.
Pikmin are easy to knock off for most characters and I'm pretty sure he has a bad roll, relative to most of the cast, while his aerials are average or mediocre for landing.
He is meant to wall out with Pikmin. I'm not sure if a huge change needs to be made, because while he does well vs some, he has some losing MUs and is not generally considered top tier [maybe high tier, but he's not on the level of some of the really busted characters as far as we know].