Mario & Sonic Guy
Old rivalries live on!
The Pokemon Trainer is still very important, even though the three Pokemon that he uses can easily end up overrepresenting the Pokemon franchise.
The main challenge with handling this matter would be whether or not any of the Pokemon veterans should have their mega evolutions represented. If mega evolutions are treated as a Final Smash moves, they won't count towards the roster amount, though Mega Lucario is probably the only mega evolution who seems to be Final Smash worthy, thanks to its Adaptability ability doubling the power of its Fighting-type and Steel-type attacks.
The main challenge with handling this matter would be whether or not any of the Pokemon veterans should have their mega evolutions represented. If mega evolutions are treated as a Final Smash moves, they won't count towards the roster amount, though Mega Lucario is probably the only mega evolution who seems to be Final Smash worthy, thanks to its Adaptability ability doubling the power of its Fighting-type and Steel-type attacks.