[Griefbringer]

I think that the main effect from such a fixed MG fired by a driver would be morale - chances of actually hitting anybody would not be too great. And it would distract the driver, who would probably be better off concentrating just on driving and letting the rest of the crew do shooting. BTW: didn't the early M3 Stuarts (WWII) have similar arrangement of two forward fixed MGs fired by the driver.

Another problem with BMG was probably that it made for a weaker spot in the front hull, that could be vulnerable to a lucky hit.

Griefbringer