My two-cents:
MG42 Gunner could be Assault Gunner carrying any belt-fed 7.62 LMG.
One or two of the Rifleman can be detailed to carry extra ammo.
Instead of an Engineer, perhaps a Grenadier who carries grenade launcher and a satchel charge. I'm rather fond of the term "Sapper".
As for an HMG, that is a crew-served weapon in my lexicon and not something you would find in a rifle or reconn squad. Too cumbersome. We can use a .50cal on vehicle if need be.
Though I'm fond of crew-served weapon systems (i.e., the M2 and Mk19) I don't think they should be integral to the standard DoW ArmA squad.
Speaking of the "Ma Deuce" (M2) 50 cal... I love it whey they talk:
https://youtu.be/71e98TXTSfk
Not even this guy would be practical:
(http://www.monologuedb.com/wp-content/uploads/2011/05/Jesse-Ventura-Blain-Cooper-Predator.jpg)