Charizard isn't my favorite. Venasaur is. I thought that was common knowledge now.
If you think I'm letting bias, get in the way, you would be wrong.
Charizard is however, the favorite of the majority. He would make the majority happy. There is a reason why most rosters have Brawl Pokemon + Mewtwo. It would make the majority happy. The majority do not want any character cut or replaced. This includes Pokemon Trainer.
If cutting Mewtwo and Roy caused major backlash, how much backlash do you think cutting the most popular pokemon of all time would create?
Thing is most of us want PT and Lucario to stay.
Most pokemon fans would be satisfied with Pikachu, PT, Jigglypuff, Mewtwo and Lucario.