you forget to add Soviet Mortar to it
and IHT suppress infantry. Just slower then HMG42, but that's the price of protection and mobility.
About Mortar Halftrack - I guess all mortars are designated to bombard static emplacements and units, so I don't see the problem of hitting moving blobs/other units. It's just not designated to do it. And the mortar shells are far more precise if you see target.