Some rambling:
I was thinking about building systems in games for a personal project and came up with something like this: The player would have a shovel and they could dig down a spot. I was thinking a minimum size be around 3 feet cubed. This could allow for shellscrapes, foxholes, trenches and emplacements as well as shell holes. Futher more there would be a system of 'mass conversation'; every time the player digs a hole their shovel gets full. They then have to dump the dirt to make a mound or a bank.
Could Outterria theoretically support such a system? I would assume a fediltiy in scale needed for this as well as a system that could handle the carving out of the terrain and of course LOD issuses.
In short, Trenchs are they technically feasible?