[Griefbringer]

My current approach is to limit on-map indirect fire support to mortars, with bigger guns purchased as off-map assets instead.

Mortars tend to be much more flexible on-map assets, since they do not need to worry much about minimum ranges, and they can change position on their own, without needing a transport vehicle. They pack plenty of punch against infantry targets, and often come in sections of 2-3 tubes for some concentrated firepower.