We have so many opportunities to make complete fleets without doing too much. Separatists is the perfect example. The Droid Gunship is already in the game as an enemy ship in the LS Geo TB. Add that and the Droid Tri-Fighter and we now have a full Separatist fleet.
The Galactic Republic has 8 ships but 2 capital ships. So add some more ships there too. Aayla Secura, Kit Fisto, Luminara Unduli, Barriss Offee, and even Grand Master Yoda had their own Jedi Starfighters. There is 5/6 needed for 2 full fleets.
Empire just needs 1 ship and the TIE Interceptor would be perfect. Although, the Empire now has 3 Capital ships.
How about some GL ships? Give Kylo his TIE from TROS & give Rey Red 5.