I see no Pokemon that don't suit him at Oak's lab.
Have you ever noticed that the strangest thing begins to happen once we see Ash with a Pokemon of his, and suddenly, we all realize that the Pokemon suits him?
Yeah? No?
Had Ash not gotten Muk, nobody would have ever seen him with it. Had Ash not captured Snorunt, nobody would have seen him with Glalie. Had Ash not captured Gligar, very few people would have pictured him with Gliscor. Had Ash not caught Gible, nobody would have ever seen Ash ever getting a Dragon-type, ever.
Yet he caught them. And now they all suit him.
Doesn't that say something about Pokemon that "don't suit Ash"? A Pokemon "not suiting Ash" can still be obtained by him just as easily as a Pokemon that does "suit Ash". The difference is that people expect to see the ones that "suit" Ash, but that doesn't automatically bar the ones that "don't suit" him.
That's a little ridiculous.
If Ash is smart, he should definitely make this generation of 3 starters fully evolve in their final stage.
Except that's more than likely not going to happen. Ash always wins with the tiny speedy powerhouses to send a good message to little kids out there, that they can win even if they're smaller and younger. He's not going to get all three evolved Starters.