NikeSXT

Yes. Objective "Neutralize Watch Towers" complete. Got "Good work, Kerry." radio message. The point is to use one shell in time. Seems it more precise that way. To get the objective done you need to kill five soldiers in total. Three standing in the watch towers, two - on the roof of security building. After its done you can disobey order to mount APC immediately and stay on the hill little longer - to use remaining shells (if any left) or just to snipe all visible enemies (MRCO in zoom mode pretty useful). When done - mount APC and continue with the mission.

Looks like it depends of your choice of action. You can start Bingo Fuel immediately or do Breaking Even first. Guess it can be the reason of starting time difference. I finished in 3am, with Kuma, Mora and 2 Gorgons. Looted 3 Titan launchers and lot of missiles - AP, AT, AA. Loaded them in my team backpacks (of course, you need to loot backpacks first). All map was cleared totally. And yes - EVERY enemy soldier, including crew members, have NVG.