Hey
Honestly, for me, FoF is designed for modern warfare encounters, where individual infantry squads are independent, highly mobile and able to deliver high firepower to the battlefield - especially if you consider benchmark for modern infantry - US army squad or similar army from highly developed modern world.
I am not export though, but think that during WW2 infantry tactics was bit different, i.e. weapons were not that compact nor multi-purpose (e.g. bolt action rifle and submachinegun) in comparison to modern gear and infantry squad was more reliant on their LMG section.
So you can of course tweak FoF rules to simulate WW2, but in my opinion better results could be obtained with other systems.
For WW2 skirmishes with around up to 16 figures per side I recommend Operation Squad. For platoon level WW2 battles Chain of Command will be good choice.
Greets