Looking good. I do like early British armour, and Caunter scheme - and here they are together!
As to MG heavy tanks - they often do far better in rules than they did in real life (this generally is true of most weapons with several barrels).
In reality the small turrets trapped lots of gasses and fumes; had poor visibility, and required extra crewmen. All of which made them poor, and hence why they were removed on the A10 (and on later Crusaders that initially had a little turret). Early Stuarts also had sponson mounted MGs that were rapidly removed. So clearly there was initial thinking that lots of MGs were good. But practice showed that they weren't.
How to represent this is a game? Especially in BA? Probably the easiest is to just ignore one of the turrets. On the principle that both where poor, so acting as one would be broadly equivalent. I suspect BA is a poor model of open desert battles, with long ranges.