Thanks Corporalslim .
Last night I had a good look at what I already had and common sense prevailed. The huge differences in size between the Valkyrie Norwegians and the Crusader FJ turned out to be exaggerated in my mind. In actuality it's only about 2-3 millimetre. They will all work fine together, which means I can stick with my original plan to buy Crusader Early War Germans, Fallshirmjager , Brits and French.
I already bought some Black Tree Design Gebirgsjager in the sale, which I like. They look much better in the hand than on the website.
I will still need to send off to the US to buy the Gorgon French Foreign Legion, as these are essential and inescapable. Also no-one at all makes Chasseurs Alpins, which is frustrating.