Just started playing with a friend, we are combining the collection. So far his rebels have been stomping me though. Any advice on a good empire list?

So far we have:

X-wing Core set

TFA core set

T-70 X-wing

Tie/fo

e-wing

tie advanced

imperial aces

rebel aces

Trying to find a good counter to his x-wings as well as figure out my next addition to the imperials to crush rebel scum!!!

Thanks for any advice.