Lancers aren't very reliable, though they seem completely OP when I play NR for some reason...
You need to build tons Escort Carriers, maybe some TIE Defenders as well and just use the their tactics against them, if you're in Era 4 or 5, build some Venators and Acclamators which spam fighters like hell (the IR also gets the Preybird and Howlrunner, which are pretty good).
On another note, if you ever play as the Alignment, use Enforcers, which are crazy effective against fighters.