Intent of the changes
M21 mortar halftrack
The changes will allow the M21 half-track to integrate more seamlessly with USF builds, and also allow it to launch smoke and support barrages non-stop.
Of notable mention is that the M21 mortar halftrack still uses the pre-nerf USF 81mm mortar. Thus, we'll have to possibly clip its autoattack and, potentially, its HE.
The M21 and 81mm mortar gained vet at very different rates. The current 81mm is garbage. If you nerf the M21 to match it, it will be worse than useless. You'll be adding a useless ability to a reworked commander.
The M21 is harder to vet because it is vulnerable to fausts/paks/diving tanks. It works best against Ost if they go really heavy on weapons teams.
If a M21 does reach vet 3, it is really good but I'd bet it doesn't happen that often. If it needs nerfing, then the Ost 81mm mortar needs nerfing also.