Millenium Falcon is not used very much in fleet arena, but it is farmed outside fleet shipments, can be farmed early on, and you will want to farm Rey who shares the M_F node at some point anyway.
The must—have ships are Biggs and various tie fighters or other target—lockets. Yes, dark side dominates fleet arena. The two Phoenix ships are ok as well, as is 5s' ship. You mainly want target—locking ships for their synergy with biggs' taunt and protection recovery. Darth maul's ship is great as a replacement.
