This can easily be done with Optimized Shotgun & with Master Takedown Perk already acquired! The trick is to initiate move from infront & a lil back from enemy as I showcase twice in this vid!
It can be annoying when they use smoke grenade & run off!
Other outposts may be easier but all I did was fast travel to Chop Shop outpost, scavenge it from bench & select Stay Nearby option & that should spawn you where I start in vid & just restart checkpoint if you fail on both guys!
Good Luck & I hopeit helps.