I'm not saying they affected his battling in a bad way because they didn't. Ash actually learns Dawn's spin dodge and applies it to his gym battles, but I'm talking about the storyline in general. It may be my bias to favor Ash all the time, but I've always thought the journey to be Ash's even though he has a couple of friends who come along. If you look at the Kanto, Johto, and Orange Island seasons, Brock, Misty, and Tracy act as sidekicks, encouraging our young underdog on his difficult trek to be champion. But in the Hoenn and more so in Sinnoh regions, the "sidekick" gets more attention and thus more airtime which makes the show have more breadth over depth. I may have a narrow mindset, but I loved Pokemon for its focus on Ash's ongoing pursuit to "wanna be the best."