I don't know, letting the enemies disperse on a hangar and then picking them off with strong but common weapons (IE RPG HEAT rounds, HMG's with plasteel ammo, grenades, etc) always worked well with me, and if you find it too dangerous to let them possibly get line of sight to your soldiers, you can just wait for them behind the barrack's doors and jump them with axes and maces once they get close to one of the doors, plus you can just lob satchel charges into the hangar continously. I've dealt with any crackdown up to mercs with this design.
The real drawback is when enemies get into the sewers. You can still get them of course, but you should prob bring along some dogs to sniff 'em out so you don't get caught by surprise.