I don't have any Scum ships (can't afford to buy those also) and the Empire is way to hard for me with formation and arc dodging. So I prefer and am way better with Rebels

Nope, I play the three factions and get at least one of every ship released. I've been playing since the game hit the shelves in 2012, initially mostly Rebels. I got into Imperials progressively, still less than Rebels though. When Scum appeared, I played that faction a lot for a while. Now I'd say that I've played all factions about the same ratio, maybe Rebels slightly more. There are still some ships that I have yet to put on the table (Protectorate, Quadjumper, Scurrg and TIE Aggressor) and MANY pilots I haven't tried. I'll get around to that eventually. :-) Competitively, I try to alternate factions, so I played each about the same. Maybe Scum a bit less. What's cool is that I managed to win at least one tournament with each faction.