I have some ideas that I feel would make the Pokemon Trainer a better character over all.
1) Removal of Type Effectiveness.
This system in Brawl, while being a good throwback to the Pokemon Series, is completely unnecessary here. This is due to the fact that over half the cast uses Fire Elements attacks, where as only Squirtle and Ivysaur use Water and Grass moves respectively. This system helped make Ivysaur the worst of the three Pokemon. I do not believe that any Pokemon should hold a distinct advantage over another of this sort, so I feel the type effectiveness system should be removed.
2) Nerfing of the Stamina system
This curse that Sakurai put on the Pokemon Trainer made it so that you would have to balance out the use of Pokemon. I believe that people should try to balance out use of each Pokemon, so I don't think the system should be removed entirely, just have it nerfed. Instead of being on the stage for 2 minutes, then having to switch, I would suggest making it double, like 3 minutes, or 4 minutes. Or, we could remove the stamina system all together.
3) Faster Switch Times
In Brawl, whenever someone had to switch, (which did occur often thanks to Stamina) The ending lag of the switch forced people to take powerful attacks when the move ended. There was an advanced technique that allowed people to switch faster, called "Baton Pass", or "Zero Switch." However, it only worked on stages with moving platforms. I suggest making it so that Pokemon can act as soon as they are released from the Pokeball, or implement the Baton Pass in another way, making it more universal.
4) Independent Pokemon Alts
"Too many alts."
If the Stamina system is still present, there should be a way for you to play as one specific Pokemon for the whole match. And YES. it can work. However, it requires every Pokemon to have their own down special, and (not required) final smash. On the character select screen, the alt box won't be any more cluttered than Ryu's. If the box is set to "Pokemon Trainer," then the player can choose which Pokemon to start as by clicking on them on the Trainer's Portrait. The alt box toggles it to read "Charizard Only", "Squirtle Only", or "Ivysaur Only." Independent Pokemon do not have stamina, and cannot switch in anyway. However, they have their own Down special, and final smash.
I know the Trainer is no where near being finished, but he is one of my favorite characters to use in Brawl, and he can be improved greatly by implementing some of these changes. The only reason why I am posting this before any real progress on the trainer has started is that if #2 is implemented, the tired Pokemon idle does not need to be made. If #3 is implemented, The animation for Pokemon being sent out does not need to be as long as it is in Brawl. If #4 is implemented, then Down Special and Final Smash animations will have to be made for the individual Pokemon.