I don't know how...
But I agree you have an excellent range of units here... There are a few gaps in aviation, and no naval units.
However, with the meshes it does mean that each country has a uniform colour scheme which would be nice.
It would certainly give tank units for the Germans, Russians, US/UK... does Sudden Strike have extractable graphics, since that game included French and Japanese units?
The Italian 2nd Generation tanks would be pretty close to German design anyway - so you could use German tanks with the dessert Mesh for the Italians... Same for Russian allies, just give them the winter meshes to seperate the two.
I don't know how much work is involved - this appeals to me since I can't build units, I could do work using pre-built models maybe?