I understand all that. Smash isnt a Pokemon game. And I'm glad Greninja made it in. No need to defend him. Where's your argument against having a grass starter? "This is not a pokemon game" is all you're going on? Charizard and Greninja are in for popularity, not what they are to their games? All I was getting at with Ash was that Sceptile was like the third gen Charizard to the anime, which was your point for Greninja. He's had more water types than grass types. He shouldn't affect Smash at all, but the show affects popularity so...
Pokemon Trainer was cut due to the fact that they decided to due away with transforming characters. We assume Squirtle is cut do to the fact Greninja is a water starter. In popularity, Squirtle and Ivysaur probably can't hold their own. Not to mention they aren't top form. But they didn't get rid of ZSS or Sheik. They kept them. Sheik could have became Impa or cut. ZSS could have been cut. But they're back, to little surprise. I don't see why they would completely do away to grass types. To me, it just seems they wanted to spread representation across the generations to appeal to people who started with newer generations. If anything, Greninja suggest that there WILL be a grass type, how could it not? Third generation had awesome starters and the main reason Sceptile doesn't have the merit/popularity that Greninja and Charizard have is that Blaziken overshadows everyone. If a remake of R/S/E happens, Sceptile could easily become just as popular. That's a huge if. My main point is there is less evidence to support there will be no grass type than there is to suggest the could be a grass type.
That being said, we'll probably get the 4 we have, plus Jigglypuff, maybe Mewtwo. 6 reps, as Brawl had, would be ideal. Plus it represents a full team. Or maybe they'll just do 5, Mewtwo's not looking likely anymore with Lucario and Greninja both having aspects that chip away at Mewtwo's qualities. To best represent Pokemon, I think the 3 starter types, Pikachu, a legendary (Mewtwo), and a wild card (Lucario/Jigglypuff..) would be fair to the game. Smash isn't Pokemon, but it should reflect it properly. Fire, Water, Grass. It's the core of Pokemon. Then all other types. But then again, look at Fire Emblem, it's treated like blue haired swordsmen protagonists are all the games have to offer.... (Sword, Axe, Lance. Then the other weapons.)