It is easy to say "lock the doors". At the HM for example - if we have some luck and do not all die against those 20 rebels with extremly big guns, then we still have to get to the compound, but often there is still somebody inside who waits to shoot us. And if we are not lucky enough to survive, then we can not break the NLR and just go back to lock it up. We will need to wait till we get another message, what means we have to wait 15 minutes and then try to deal with the same people again, who can easily kill us for the second time. Also if you look at the picture, they have 18 people, 8 of them have a lvl 5 vest. Furthermore, I am not able to see all the weapons, but it is atleast 1 zafir, 1 mar10 and a ton of 7.62's/MXSW's. So surviving will not be easy for those 10 MK20's who show up