A thing that still feels like it's missing is to have vulture droids as land aircraft. Maybe the easiest way to implement it is to have the two existing vulture hero units also function as land units that can morph back and forth from flight to land mode.
The confederacy has a doctrine mostly focused around mobility and firepower so a light fast air superiority fighter feels like something they should have. A good thing could be that it can only attack air targets while in flight mode and only attack land targets while in walking mode.

Another idea could be that after you get the additional vulture droid upgrade you will get a single free vulture droid unit every land battle if there is a ship affected by the upgrade in orbit. It would fit the confederate's enormous droid numbers fairly well.