Don't forget the benefit of monitors or battle stations, amram. If you know where the wormhole is, it's pretty simple to tug suitable units there. And with just one small engine to give them little dodging capability, or without any engines, more tonnage can be devoted to armour/shields/weapons. They don't have to be big either, because you can just keep a shipping line churning them out. Crew deployment is a problem but you can create a R&R ship with 2 entertainment modules and have it visit the location of the "forts" every 6 months. Granted, I haven't tried that method since Steve added crew morale/deployment in to the game, but before then, it worked as a tripwire, first line of defence. Or you can use mines of course.