Maz, I hear ya....really I do and I would love to see TWI or even the team I work with now take on a project like that. BUT, it isn't as simple as...all the material already exists, use that.
There are tons of things that the average gamer never sees. Sure we can read the blogs and gamer sites and even have some very knowledgable gamers pipe up on forums but I will tell you right now having gone through the COD series with a test group called The Visioneers and now working with the RS team, there is more to making a game than just well it exists, use it.
The dev team has spent hours, more hours I can say than most gamers play this game, studying the history behind what they are trying to convey, poring over maps, images from battles, reading texts about the battles, etc.
Sure, we have some great modders in our community, ask them how long it takes to make a realistic map with all the assets available, now do it from scratch and make 6, 7, 10 or even more maps to go along with the WHOLE package.
Give it time, we have some great mod teams in this community, so let's see what they can do.