I'm pretty sure to achieve that you need to follow the steps required to make an Infantry only map but make the necessary changes to the SCAR and then add the names of the ATG's and mortars instead of the vehicles.
Yeah the thought had crossed my mind... Only thing is, I don't know the names of said items for SCAR coding. Any way to retrieve this information? I have been looking online for a bit but to no avail..
EDIT:
Just had a bright moment after drinking the rest of the coffee. I went to look in races/crews (items) in editor and found the names. Epic.
EDIT #2:
Ok, so I found the names, and I have been studying the infantry only SCAR document. Since all the disabled units are infantry weapon crews, do I put them in instead of the called in reinforcements? Since only the 120mm mortar crew is called in, the rest is produced in buildings.
For example, it is unclear to me where the Ostwind Flakpanzer is disabled in the document. I'm assuming all vehicles are turned "off", and the creator added the called in special vehicles to the list. If this is the case, I can't just swap out the vehicles for the crews. I would have to be specific. Now I'm not a genius at this sort of thing, so some help would be really appreciated.