You guys should really try holding guards up, get near then just aim your gun at them, they'll surrender and you can interrogate them or order them to get on the ground, it's better than a tranq in the sense that they will not get up unless the base goes full combat alert or another guard gets them up. Also, if you have a guy on the ground you can just aim at them and they immediately give up, so if you tranq a guy long range you can walk up kick them and immediately interrogate them instead of waiting for them to get up and grabbing them. Another useful tactic is diving into guys which knocks them over and you can aim at them even from a prone position and they'll surrender.
MickeyKnox's comments