Today I was playing a multi-player game on gamespy and I sent about 3 or 4 strike mechs into another guys base to investigate and maybe kill of some workers ;) To my surprise, these guys can kill a trooper in two hits! It turned out that he was waiting for me with at least 40 troopers, and I took them all out with 4 strike mechs. They were finally destroyed when his ally brought an A-Wing and totally destroyed them. However, I got that guy to resign and the rest was easy :D
Actually I believe that a lot of tie bombers and a lot of bounty hunters are unstoppable.. especially if they tone down the anti-air units WHICH I HIGHLY SUGGEST.