"If I could use stormtallons to escourt Stormravens in my BA army, that would be awesome"
Well, guess what, with Allies now I can. Take a a primary Codex marines detachment with 3 stormtallons and some bikes as troops. Then add a BA allies detachment with an HQ, a stormraven, some death company and a death company dreadnaught. Stormtallons can be attached to a unit and come in on that units reserve roll. The Stormraven has 3 units in it (including the HQ) and is a unit in itself. Attach all 3 tallons to the raven and its contents. Everything comes in on one reserve roll, probably turn 2.
Cool beta strike!