Um, mages have one self combo, as do birds. Birdies have a couple combos with mages and a combo with bears. For the top two combos in the game, birdies are one component. I would say that's good.

As for helping keep mobs pinned, avian scream is very good. It's very good for a group of avians without a tank. Maxed out repulse shot really repulses, so for better control, you might consider not maxing it.

If you ever play a warrior, please please please do not overuse stomp. I really hate my beautiful gathers being scattered about and losing some who knows where, only to have to chase them down.