The easiest way to do this is by searching for easy contracts.
Choosing "The ICA Facility/The Final Test" and "1 Target" in the search options you will find a lot with one of the nearby soldier as the target!
Usual target looks like this:
I completed 10 of these and a featured contract for the other achievement and it popped.
Not sure if you need to do 10 or 11. I had already done the featured contract when going for this!