Personaly idc, I will attack both faction. The only difference is:
a 14k hp imperial wont be attacked but a 14k hp pub will die.
Since the empire have,I think, the biggest population, imp vs imp is easily acceptable but pub vs pub is not the best idea.
However I've been ,many times, on an Ilum channel where the pubs number was bigger than the imps.
If you're making distinctions, then you do care.