Why don't any of the main characters have battles with random trainers anymore? Everyone they battle seem to become rivals. I'm not even necessarily talking about a COTD when I say random trainer. I'm thinking back to episodes like in the Orange Islands in the episode featuring Prima. Before battling her, Ash battled a trainer with a Persian and Tauros. They battled and then that trainer left. That was it. I'd personally like to see some more random battles like that, rather than see the trainers get new rivals or spend a day with them every time.
What are your thoughts? We would get so many more battles that way too I bet.