I like how it went into discussing damage, which is fine. Survivability of 120mm isnt fine, not its damage.
Its being placed in a tier list with pack howi and IGs, but both cant retreat and die fast enouth even to weaker counters if played incorrectly.
120mm not only has supperior firing profile (since mortars arent effected by shot blockers as much) but also have the best survivability and retreat on top of it. Its just too much even for a commander unit.
I would have undertand if 120mm had the shittiest range therefore it needed its survivability, but its not. There is not a single reason for a unit, which already can outrange almost all awaible counterparts (untill rocker arty) and effectively stay out of a danger, to have surviability of a frontline unit and firepower of a glass cannon artillery piece.
IGs at least have the worst AOE and the wost barrage, Pack howi dies like a fly if placed agressively or being fired upon but 120mm dont have any of mentioned disadvantages.
There is some trade off between damage and survivability.
The PaK Howie is usually similar to even better than the 120mm. The leIG is somewhere in between normal mortars to the Howie/120mm. Usually closer to the mortars, but takes the first place. We also should not forget that the 120mm costs more population and compared to the leIG, also MP.