Icamp, here is a slight update, i`ve altered one of the entrenchments so that it`s reinforced with sandbags all around (nr.1 on picture). The three other are as before, although nr.2 is partially stacked with sandbags. The sandbags are not highly visible though, they are small and not stacked like a row of tincans at Wallmart.
Imp, yes a 50m hole is way too big, but then so is a 30m long Sherman tank. But if they were made to scale, we would hardly see any of them at all.
I guess we have to accept that much on the map is abstractions one way or the other. Anyway, the entrenchments are for vehicles and guns so will have to be made to fit most of these inside, thus somewhat oversized.