Heading to Peter Pan first is a much better idea. You'd be on and off before 9:10. Then hit up Ariel, then ride her ride. You'd be done with all three by probably 9:30 or so. Logistically, it also makes sense to hit Peter Pan first. It's much, much closer to the castle than the Ariel stuff, so you'd be backtracking to get to it if you went in the direction of Ariel first. The Little Mermaid ride has a monster capacity, so lines don't build as fast as they do at Peter Pan. You can then wrap around and do Barnstormer, Dumbo, and Pooh, and you'd probably be done with them by 10:30. You go to Peter Pan at 9:45, you'd only have those three attractions (PP, LM, and Ariel) done by 10:30, as opposed to getting 6 in hitting Peter Pan first.