You've shown a funny example which clearly demonstrates how it wouldn't work. I don't know what developers think about it, but in my personal opinion, there will be 4 human playable types (Hero (classic), Fat (Vic type), Normal (farmer type) and slim ("junkie type"), 1 playable ghoul and super mutant type. Most likely, others will only replace the current NPC's models, so it's doubtful that kids or midgets will ever be able to carry minigun. Though who knows, maybe developers will ask us to make a female midget and a kid to make them playable too.