I've always thought that it would have been better for Red to fight with his Pokemon, rather than just command the Pokemon from afar. What I mean is something, perhaps, like calling out Pidgeot for his up-special, which would carry him upward as Brave Bird is performed; calling out Diglett/Sandshrew for his down-special, which causes two traveling burrows in either direction that entrap other fighters (Dig); and et cetera... Too lazy/tired to come up with the rest of that potential moveset.
The way Pokemon Trainer is in Brawl just doesn't feel right. It's kind of off-putting to just see Red standing there in the background, especially when he's on some random floating island.