Yes, it was definitely a little different during the early Kanto, not just because Veronica was still fitting in her role, but the voice directors were still deciding how they wanted it. I agree with Silver though, it somehow makes sense character-wise. TRio took some time as well. Rachael had Misty more or less figured out from the start. Brock's wasn't quite himself until after his debut episode, but he was of course a super serious gym leader until leaving with Ash, allowing Eric to open him up a bit more.
I support Save Our Voice Actors, a Pokemon fan group in favor of returning the voice actors in the anime dubbed by 4Kids (seasons 1-8). facebook.com/saveourvoiceactors