I would suggest keeping the number of suppliments to the barest minimum. I agree that C&T is a good idea as is Spell Law, beyond that every optional rule in every suppliment needs evaluating as to whether it fits with your vision of M.E. (without the full stops, that looked really egotistical!) and the game you want to play. I was in a game where the GM had lots of armies involved and he used War Law I think.