I had a basic stratagy for clearing most areas.

Pick off singe stragglers with non-lethal take downs. Groups of two when I got the double take down Augment.

When I could no longer do that undetected, stay a bit back and start capping heads with a 10mm pistol, the most useful gun in the game.

I did this on the hardest difficulty, and didn't even make use of my Typhoon until the second boss fight. I rarely play shooters, only one I play a lot is boarderlands.

Perhaps I just got lucky and stumbled across the easy strategy.