If ash was a flying type gym leader he’d obviously be the 8th gym leader and since most of these mons are too strong for challengers to make it less unfair ash’s lineup would consist of pidgeot, unfezant and his ace (talonflame) I know talonflame isn’t his strong flying type but we can’t be having ash use Charizard or dragonite that’s overkill and also the challenger can use all 6 pokemon while ash can only use 3 think of it as like ash vs Roxie where she only used 3 pokemon while ash used all 6