In the Core Set, you really had a big difference between the Empire and the Rebels. The Empire had the big (medium, really) ship and a lot of light fighters, whereas the rebels had light ships and heavy fighter-bombers.
With wave 1, the Empire got a light(er) ship and heavier fighters, whereas the rebels got a bigger (medium) ship and also some more fighter options. Nevertheless, they are still the only ones with a speed-4 corvette, whereas the Empire is the only one with a close-range mangler.
Yet, when Wave 2 comes out, both factions will have a large ship, both will have a medium ship, and they will both have close range manglers (Gladiator and MC30 respectively) and they'll have fast-attack corvettes. The Neb-B will be the odd-ship-out, but somewhat negligible.
So, how distinct will the factions really be? Are they more than different shapes on similar capabilities?
If so, is that a bad thing? Should they be more distinct from one another?