[Imp]

I am a bit confused changing the hex scale will not stop change the number of shots a unit takes against a moving target so it will still move the same number of hexes for the same number of fires. Makes no diffrence to the game really apart from time and now a map does not cover much area.
Are you sure about vehicle move speeds I worked out some years back and they are close, certainly way closer than the competition.

Regarding ROF it is affected by experience, 3 for an ATG is low.
Unsuppressed firer
ROF for infantry seems fine to me they can normally shoot at another infantry unit in every hex it enters.
Vehicles is fine to within the confines of the game. That ATG will get a ROF probably of between 3 & 6 depending on the units experience in the game.
6 aimed shots a minute I would think is very good for a gun by modern day standards vs a moving target.
To me the current setup feels right normally I can handle things but sometimes my guns get overwhelmed.
The big issue with changing hex scale to 10m is accuracy a WWll tank should be pretty accurate out to 30 hexes let’s not even think about modern stuff. Spotting will be all wrong infantry will often be under 100m before seen.