Blofeld, no point adding too much to soldado's image, which is worth a thousand words. But I've just finished creating four WW2 'platoons' for Chain of Command (Brit southern Europe, German ditto, US Army mid-war and German paratroops). The question is not so much size, tho the Perry figures are quite small compared to many competitors, but proportion. And the real issue once you get down to it is the enormity of the heads on the Warlord plastics (weapons are a little bigger too).
Had to draft in some Warlord metals to the British platoon (for specialist engineer roles), and sliced off their great big helmets, replacing them with Perry ones. Not ideal, but workable. With my German paras I needed some figures with panzerfausts and one or two others to supplement by Perry ones. I equipped them with the covered helmets (and one with a peaked cap) so that the disparity between the uncovered helmet and the Perry one was not so obvious.
EC