Which one

In Big Daddy they had both Dylan and Cole play Julien. I'm almost positive it was Cole who played the more quiet, shy Julien and Dylan who played the more outgoing, fiesty Julien. But then u saw Cole played Ben on friends. And Ben was supposed to be kind of fiesty and sassy (like Dylan) So now I'm confused. Would anyone happen to maybe know this even though it's obviously not something tons of people pay attention to. But they also did this on full house. Mary Kate played Michelle when she was supposed to be more out going and sassy, and Ashley played Michelle when she was supposed to be more quiet and shy.