Not positive what criteria are used by HTC to decide whether something should be added or not, but it's generally accepted within the community that it would have to have been deployed and flew combat sorties to be considered for addition. You have to draw the line somewhere and that seems like a good a place as any otherwise you open up a whole world of mods, and experiments. To me this would fall under the 20mm for F6F-5's, the P-38 could also carry a torpedo as could the B-25 I believe, they also tried a B-25 with 20mm cannon in the nose instead of the standard .50 cal straffer (if I remember right, don't have the book in front of me). And that's just weaponary what about fuels, additional gun stations on bombers? etc. etc. it's a whole can of worms that I think the general consensus is should just be left closed.
