The Ost mortar is not OP. The vickers thing was just a bug or 2 extremely good hits on the Vickers which can happen, though it doesn't happen very often.
The Ost mortar IMO has a perfect range and does maybe a bit too consistent damage, but this damage is needed for crowd control against Allied blobs, especially in team games. Additionally every Allied faction has at least one mortar that outranges the Ostheer one
- 120mm Sov mortar has more range + more damage + 6 men squads with the ability to survive with one man left (which is absolute BS). Though it is doctrinal and shoots slower.
- UKF mortar pit has more range + shoots twice + has brace + can't be stolen + Shoots faster with garrison bonus. Though it can't move obviously.
- USF mortar has more range (or same, don't know) + faster fire + better accuracy.
The only mortar that really is worse than the Ostheer one is the Russian BM41.
When playing as Axis, I am ready to sacrifice a squad of Volks/Grens in order to get a 120mm/USF mortar. Simply because currently they are kill farmers behind your lines without any big effort. It speaks for itself that currently you see about 3-4 mortars in 2v2 games per side simply because the killing and wiping potential of mortars is so huge atm.
1-It's a bug. The crew should die but the weapon itself must survive with roughly 50% HP. Vickers/MG42 etc have 350HP and mortars only do 80dmg per shot.
2-Remember that OH/SU mortar cost 240mp.
-120mm cost 340mp and it takes double the amount of xp to vet up in comparison to normal mortars. You hit vet 2 (40% barrage recharge and less scatter) and 120m is just vet1. You get vet3 and you actually have more range than the 120mm mortar till it gets to vet.
It has equal damage but better AoE, but mostly on AA which is REALLY slow. Barrage AoE is reduced in comparison.
-Mortar pit is 400mp but they are 2 mortars (for some reason one is worst than the other). What is shitty about it is that it works really well when left afk. (IMO reduce AA range and make it more dependant on barrage aka imput player)
-USF is more or less a clone of the OH mortar. Difference is: it cost 260mp, it gets better vet1 (less scatter) and it has better barrage (more scatter but 1s faster rof).
All mortars are noob friendly on live, specially once they get vet.