Being heavily outnumbered has very very little to do with your side losing PvP matches. Regardless of your overall server ratio, when you enter a WZ you are put in a match with the same number of people on each team, making it even. If anything being outnumbered should give you an advantage, as you dont have to wait in ques for WZ like the empire does, giving you a chance to get far more pvp commendations than the empire can get in the same period of time.
TLDR -The issue is not about your faction being out numbered, but about the people you play with sucking at PvP.