Which WWII army and which period are you trying to emulate?
I assume only the primary powers
Germany is easy enough to simulate, mechvets for panzergrenadiers, Leman Russes for Panzer IIIs/Panthers, Valkyries for Stukas, Vendettas for Me 109s. Late war Volkssturm troopers could be simulated via Conscripts. Amusingly, the V-2 could be shown well by the deathstrike,
The Soviet Union would be largely platoon-based with a smattering of commisars for early-mid war, late war you could mix in some more advanced troops like those above. Perhaps even the manticore representing a Katyusha.
America would be largely similar to Germany, excepting the Volkssturm and V-2.
Britain: See Above
Imperial Japan is very difficult to simulate on land, as in general it was rather ill-equipped, armed with mortars and relying much on air and naval support. A straken-based platoon could work for a flavorful banzai charge, though more realistic would probably be static and dug-in troops in cover with a smattering of heavy weapons and a covering force of flyers.