Anonymous
The problem I have with the “set the perimeter concept” is that the perimeter and the area inside are related. A longer perimeter encircle a bigger area that gives you access to more resources but requires more manpower to protect. A smaller perimeter could be easier to defend but what you can have inside might be limited.
I live in an area with mostly 5 acres lots. Most lots are half wood, half grass. Not a bad setting to have some goats, chicken, vegetable gardens, space for storage. Most household are 3-4 people with some being children. Let’s say 4 of us pull together, we will be doing ok for most aspects but we have 15 people at most to defend some 3700ft of perimeter 24/7 some of which is wooded. Even using some advance alert system, it is a lot to cover.
On the contrary, a development with small size lots can easy have 80 people living in it. Fairly easy to cover the perimeter but there is hardly any space to grow anything and most of the time they rely on municipal water making the resource available to those people very few.
So the common military strategy of selecting a favorable position and set the perimeter might not so easy to implement in a SHTF situation when people have to deal with a location that is what it is and cannot rely on a couple of Apaches coming in to provide extra fire power.