So as of now, Stalagg is heavily horde favored and HS is heavily Alliance favored.
While a merge is out of the question (it would be doable, but the names, etc. would be hell to manage and Blizzard seems to opt for the easy solution), allowing faction based xfers seems like a win-win solution.
Stalagg is roughly 98% Horde and HS is close to 93% Alliance. I’m sure that if Blizzard allowed Alliance to xfer to Stalagg and Horde to xfer to HS, you would see both servers balance out around 80/20, which is much better and solves the AQ gates problem.