Turreted machine guns and fire control values

[dmnt]

Combing thru the Finnish OOB I came across the fact that game-wise the turret machine guns look worse than AAMGs in general: There's no increase in accuracy or lethality but the TMGs lose the ability to AA fire.

I didn't want to file a report on the OOB thread without first discussing what's the general line of TMGs. If there is an internally operated turret with electronics in it should it have fire control values larger than 0? Or is there some requirement for the operations when this should apply?

What about turreted MGs that have an AA capability? They should still be in class 4: AA capable MG?

Finnish OOB has units 048-055, Patria APC/IFVs.
XA-180 and XA-185 have NSV AAMGs without capability to fire them from the belly of the APC. XA-203 and XA-360 (AMV) use turrets, although only AMV version has the weapon 69, 12.7 mm NSV TMG. The versions with autocannons do have fire control values of 12 and 30, no AA capability.

So when exactly should the turreted machine gun or autocannon be AA capable and when should it have a fire control bonus?