You kill juggernaut since he roams the map and the only guard spawns for when you pick up the primary target are at the main gate and we mostly kill the other guards since there most likely to have key card and gives us free roam of the base
If unlucky and you kill some guards at the wrong place the respawned guards can detect dead bodys. Btw they spawning 5 new guards, and not just one like someone wrotes here.
If you have killer RNG you can do the whole thing in less than 8 If your rng sucks you can do it in 9:15. Without killing that much guards. But obviously the juggernaut. Still a solid run guys.
the path taken by the guy in the video is quite dangerous in truth. you and your friend could do it by killing just 6 guards and having the elite challenge (the guards: the guy facing the sea, the duo in the corner facing the sea and the 3 with a red sight zone are my 6 guys)