I am not sure why you are against moving unit into doctrines especially since "new" units have been move to stock.
The USF tech changes have made the Pack and mortar overlap too much and have practically similar timing and that creates a number of issues.
Currently USF has been move from having limited access to support weapons to have more stock access than they actually need.
Mortar, Pack howitzer, Scott, Sherman HE, Major barrage create a situation where these unit overlap and will either be OP or forgotten.
The problem of the Pack howitzer will not go away even if it is redesigned because of it's timing. It available to soon to the mortar, has a tech cost, so it will either be OP or UP.
Even if one compares it to 120mm mortar it is superior while being stock and available earlier.
Because i prefer giving factions more tools, not less.
A whole "NEW" unit which remove the capability of Rifles to use smoke.
Mortars no longer overlap with Pack Howie as much since the moment they had all (mortars) become less lethal. Complaining about Mortar/Pack Howie overlapping with Scott/He sherman is like saying that AT guns and TD overlap too much. The barrage on the major will only overlap the moment it's free.
The timing on the Pack Howie is not the issue. No more than a Land Mattress or a Stuka arriving early atm. Would it be much better as a different type of unit sure.