The anime usually influences Pokemon choices. Greninja was not one of those cases. Incineroar could slightly be another case like Jigglypuff, but a key factor is that it might not much matter. It is clearly meant to be promoted as Ash's Pokemon, but that won't do it alone for Sakurai. He still needs to see the character "dance".
Pokemon Trainer is an interesting case. Charizard and Blastoise were the only known choices Sakurai went for, and changed Blastoise to Squirtle for balance/making it easier to imagine a moveset. Last one was Ivysaur. Choosing Red's design wasn't as simple as "Red is iconic" alone. Red is actually less known than Ash due to the anime having a significant worldwide influence. Some still think it's Ash, not Red's design. Yes, I've seen it before. Now why it is so interesting? Because it coincidentally matches Ash's Pokemon too. Charizard and Squirtle are severely popular in the anime as well. And Bulbasaur was the only one who nearly evolved, making the Ivysaur thing kind of funny. But in reality, no, it wasn't an anime pick. The only thing of note otherwise is Pokemon Trainer is not treated like he's Ash in Smash itself in any way and is just another generic trainer. He's only compared to Ash and friends at best. But this was intentional because to fit the general idea of how the Pokemon games work, you always chose your name. So Pokemon Trainer was intended to be a representation of the Class, not the actual original protagonist character. Leaf's design doesn't change this either, as it's the same point. All their costumes reference other protagonist options, so people have even more choices. And it's pretty cool he went that route instead of the silly idea that it has to be a "specific character". Villager is another example of the generic class idea, with the only thing of note is that Villager isn't based upon a particular canon character design-wise instead. Well, story-wise, if you will(as AC has no real story).
was picked for the games. The starters may be iconic in the anime as well, but I think they were solely a game-based move.
