I've been giving it some more thought and I think if you want to get this done then there will have to be a bit of rather boring data input from your side. Basically, I can set the thing up so that you have all the names you need, a nice list with all the players and their stats you can put in, and all fitting into the system.
However I can't access the CMED source properly, and even if I could it would not be able to change some of the fundamental things like the formations etc. So to get the thing to work properly, it looks like you're going to have to change the players manually, because if you do, you can work by shirt number and position, and then when the computer does the formations and so on, it will balance out.
Reckon you can do it? it's about 1500 players. As I said, I'll have cut out a lot of stuff for you by making all the name available but other than that, I think it might be tricky.