cause real world trenches are deep as to protect the people in them.
Trenches warfare is evil as in the trenches you are safe that is until the mortars come.
Most trenches where a two line system like so
these trenches would be to deep to shoot out of or into, though airstrikes and mortars could hit them, cause of this many trenches has "roofs" on the rear line. (not shown in image).
Most trenches where 8+ feet deep with eitehr shallow areas for firing, elivated portions, or pillboxes dug into them.
Ok some one needs to make a true trench war, map.
hmm. I need to ask the soldier about something as the d-day map has some good items for a true seige map.