The secret is using smoke, flashbangs and long range fire. Smoke is really just too good. Enemies should have the ability to blindly fire into smoke or something, maybe. Flashbang removes reaction fire and TUs for the next turn, so a flashed alien is practically dead. The aliens completely murder me in close combat, because their reaction fire is so deadly, so I try my best not to be there. Also, losing soldiers or half your squad every now and then is not the end, so maybe you just think you'd be totally raped. : )