Somehow I missed this back in April; my apologies. Basically, it’s tactical not-quite-artillery.
Picture an armored tarantula about the size of a compact car, with a coilgun and a fancy sensor suite strapped to the top. Now picture it wandering around the battlefield such that no two shots appear to come from the same location…
skitter skitter skitter BANG skitter skitter skitter BANG skitter skitter skitter BANG…
The individual slugs aren’t all that big, compared to regular artillery/ortillery, but what they are is extremely accurate, because it makes exceptional use of the battle mesh to put just the right shot, on the right part of the right target, at the right time, to maximize damage. Tactical sniper-artillery, if you will.