There's still a ton of stuff to be added to this game, and the AAMGs are one of them. You'll also have the option of firing SMGs from open hatches at infantry too!
All of the Sherman variants from Patton's Best have now been added in. Lots of extra stuff that later sherman models have, like stabilizers and smoke mortars, haven't yet been added, but at least you can get the benefit of better armour, a loader hatch, and the 76mm main gun.
The original to-hit and to-kill tables from the board game are simply pre-calculated odds based on the core Advanced Squad Leader system, with some adaptations. If you've ever wondered why a roll of 1-3 is a critical hit, it's because the odds of rolling an unmodified 1,1 on a 2D6 are 2.8%. Most of the combat system for AC is now in a format where I can slot in new vehicles and units very easily. It was a lot of work, most of which is not visible to the player, but it does means that in the future, adding new player tanks and enemy units will be very straight forward.
I also just brought the window height down to 744px so it should fit onto a 1366x768 screen.