OK, so following Wave 9 the three factions - Rebellion, Empire, Scum & Villany - were all balanced in terms of number of ships available for each.
Wave 10's initial announcement of 1 Rebel, 1 Empire, 1 Scum ship was then not so surprising, as it maintained that balance between factions.
Enter Rogue One, and the U-Wing and TIE Striker. The announcement of these ships bumps Wave 10 to 5 new releases, and pushes the Rebellion and Empire's numbers ahead of Scum.
So I guess it would be fair to expect Wave 11 to be a 4 ship wave - with 1 Rebel, 1 Empire and 2 Scum - to once again restore the balance between factions. Thoughts?
