I feel WW1 works better. Theres surprisingly few heroes in The Great War whereas WW2 has Superhumans by the armful. Also ties into the recent Emancipation of wonen and their rise in the workforce. Plus WW1 was when the last vestiges of the Victorian era died, mysticism, chivalry etc and Diana can represent that to a degree, the last of a classical Era fighting back in the first truly industrialised war.