It wouldn't make much sense to have TWO Steven Stone's in the anime, it would be like saying either THAT episode is non canon, or there are two Ash Ketchum's running around, and this Ash is identical to the Ash we know except he's voiced differently.
As for different VAs, isn't it as simple, as they asked the original VA if he wanted to reprise his role, and then refused to do so and therefore they had no choice but to recast the role? I mean it's hard for me to assume that all the past VAs of one off appearances who barely voice characters within the Pokemon anime series to just jump right back into a role that's 10 years old.
There actually might be examples of VAs returning even after longer, and only ever voiced one character that just suddenly made an appearance again, that's fine, but we'd have to assume that the recasting of the voice wasn't malicious in nature, as in, they didn't remember that this guy voiced Steven in that one single episode more than a decade ago, but rather he simply refused to return for the role.
Though I don't know if that's actually a thing, for a VA to refuse to come back, and their VA is recast.
You're allowed to forget things, people don't remember every little thing they've ever seen.There's a difference between that and Dexing a Koffing though.
How? What do you make of Ash actually recognizing a Pokemon and yet he STILL Pokedexes it?
