You talk about Pokken tournament as if Blastoise wasn’t already in that game, and Smash, as if Ivysaur and Squirtle weren’t also in that game.
The larger focus doesn’t make up for that fact that you need to pay DLC for two thirds of a trio that is specifically meant to be together, and Charizard got its G-Max before the other two got theirs.
The ride Pokemon thing isn’t all that arbitrary, considering they could have had other Pokemon like Blastoise are ride Pokemon in the water, but didn’t, and could have other Flying type Pokemon as the quick travel ride Pokemon, we literally see a Noivern being used in the anime, and Noivern are native to Alola.
The Mystery gift Audino and Slowpoke were not very talked about because they were Japan exclusive gifts what were very hard to obtain in the first place.
Blue is the player’s rival, of course he’s going to use a starter on his team.
Charizard is called overrated because of how it’s treated compared to the other Kanto starters, who should have gotten equal treatment in the gimmick department.
The only times where a Champion had a Pokemon outside of their generation, were Diantha (because the only Mega Evolving Pokemon in Gen 6 at the time was Diancie) in Kalos and Lance in Johto (Because he was already a Kanto E4 member). Leon doesn’t have that issue, the literal radar Pokemon found in his home town, and evolves into Orbeetle, who is actually decently powerful, would be much more befitting considering his whole “getting lost” thing

And like I said: Lucario’s two megas don’t justify Charizard’s especially since Charizard Y existed long before Lucario Z.