We know that this game still in state of beta testing, especially with newly added Normandy campaign but giving UK Commonwealth weaponry to US force seem very off to me, i suggest to remove or change some weapon that historically matches with that would present during invasion of Normandy
USA
Ross rifle → M1903A2 or M1903A3 (Ross rifle is obsolete WWI rifle, only in use in small number during WW2 especially with the British Home guard)
SMLE mk 1 → M1 Carbine or M1903A1 (Regular US troop engineer wouldn’t use british WW1 small arms obviously)
M3A1 → Thompson M1 (A1 variant of grease gun only appears from December 1944 in small numbers)
PIAT, Bren gun and 2 inch mortar → M1 Bazooka, M1918A1 B.A.R and M2 Mortar ( for obvious reason)
Germany
Mannlicher 1895 → Pre war Kar98k (Mannlicher 1895 only in use by Volksturm and police unit)
FNAB-43 → MAS-38 (any captured French weapon can be added to German squad since German unit stationed in France usually given captured French small arms)
Breda Mod. 30 and Beretta 1918 → MAC 24/29 and MP-35 (again, same reason as above and any captured Italian small arms would likely be used by German in Italian front)