I feel like Izzy, Hitch, and Sprout were the ones bringing in the comedy in the movie. But since then…yeah, Pipp’s definitely the one designated for most of the jokes, and she’s the actual funny one.
Which in it of itself is funny ‘cause it’s very clear Izzy is meant to fill in the same comic relief role as Pinkie, and she’s nowhere near as funny as either Pipp or herself in the movie.