So the commedation for assassinating enemy covenant or forerunners in spartan ops is actually amazingly easy to do this week.
So 5:3, there are a lot of covies, who are too preoccupied with other business to really notice you running up and assassinating them. Be prepared to die alot, but this is the best place I’ve seen so far.
Also can be completed easily against Elites by doing a close range Plasma Pistol blast, making them go into their “ROARRRR!” stance, then you quickly sprint behind them and assassinate.
That’s all, just thought I’d share that.
I maxed the commendation on 4:1. put it on easy and use camo. You get two right off the bat. tons of grunts in this mission. all you do is get close to them and put your camo on for a second. they all get scared and start running away from you = easy assassinations.
You can do it on 4:1 against the 2 grunts at the beginning.
Maxed mine on episode 4. Tip,against covenant, use hologram right in front of them, 90% of the time they will get scared or startled or angry, giving you a nice 1-2 seconds to walk behind them. This doesnt work as well on the prometheans though 
I done the commendation by replaying spartan ops a lot?? 0.o