You are completely wrong.
Brawl had 6 pokemon reps, and had 2 more planned. So out of the 46 character roster that was planned for Brawl, 8 of them were to be pokemon reps. We're probably getting around 50 this time, and the 6 Brawl reps + Greninja and Mewtwo is pretty much the perfect pokemon representation right now. The fact that Greninja plays nothing like Squirtle and that they weren't shown as pokeballs indicates more strongly that they're returning. And the fact that Charizard was revealed first doesn't mean anything really, Zelda and Samus were revealed months and months before Sheik and ZSS. And with 4 starting pokemon already, I'm pretty sure that Jigglypuff and the rest would all be unlockables -- Therefore not announced until after release.
Mario had 4 reps on Brawl (in Sakurai's scale of representation at least), and 5 planned. So the original plan was for Pokemon to have 3 more playable characters than Mario.
People need to accept that Pokemon has a huge cast of extremely versitile and unique characters, add that to the fact they're one of Nintendo's most profitable franchises and it's clear to see exactly why Pokemon gets the most amount of playable representation.