Someone popular within the community could try to bring together all these WW2 Modifications but everyone has so many different visions on how to approach Hearts Of Iron.
I've played various modifications but the ones you are insisting is of the few is CORE, StonyRoad and the Compendium Mod. But to be honest, I like all three, but the Compendium offers me a great deal of fun above the rest because it aims for Artificial Intelligence, offers great events, New's, it's own unique and original technology tree, cetera.
What happens if those mod leaders come together and what to do different things that conflict? It just wont happen, you should be very happy that we have so many similar modifications because in actuality, they're extremely different in what they offer, even if they all offered their own original technology trees.
One aspect of the WW2 modifications I was always upset with was how they handled "Heavy Tanks". Like the KV series, Matilda's, IS's, other heavy tanks as technology. If any of them brings this up to me I'd happily share my concerns and suggestions.