Here guys, we have the culprit. Burn him on the stick!
I'm just saying that they might have been too lazy to use just the model so they ended up using the entire M1 81mm mortar entity.
Speaking of which, the M2 60mm mortar and M1919A4 Browning HMG models are in game but are not animated, as well as the 3-inch mortar being glued to the god damn emplacement instead of being it's own thing.
Relic's laziness really has no boundaries.
You can't even imagine what kind of trouble SneakEye (All Units creator) had to go through just to be able to use the 25 pounder as it's own separate thing in his mod.
So yeah, just don't expect anything differently with DoW III, I know it's not the same team working on it but it's still Relic, under SEGA, sadly.