I recently started rewatching the series from the beginning, and starting somewhere in Johto Journeys, Brock/James are pretty much the best part of the series. Pretty sure Eric Stewart (the VA) was a producer or something as well? It seems to me like he had a hand in helping write a lot of Brock's and James' lines, and they can get pretty silly (in a good way.)
Example:
In the episode Moving Pictures of Johto League Champions
Old Lady: I can tell you how this lodge got it's name, but it's a long story and I'm sure young people like you have far better things to do...buuuut I can tell you if you REALLY INSIST...
(The kids all show exasperated faces, the camera pans past each as we hear their inner thoughts:)
Todd: We're stuck now.
Ash: She's getting ready to tell her whole life story.
Misty:We'll be here forever.
Brock: I wonder if she has any string cheese.
There's really no reason for the weird line, his lips aren't moving, so there's no "dub effect" towards trying to match the lips to the words. They just wanted to make Brock say something weird. It's not exactly highbrow humor but I notice them doing stuff like this more and more, usually with Brock, while James' silly lines usually have something to do with the inside joke of his ambiguous sexuality.
The episode before that, UnBEARable:
The Rockets have been stealing corn from a field and selling it to earn money.
Jessie: Fresh hot buttered corn!
James: Roasted corn on a stick! The corn is great and the stick isn't bad either!
