Oooo, excellent point!
I, being a newbie, will be watching this post closely!
I would suppose that the other factor is force technology -- like quality of armor, arty, air etc. -- that would seem to be harder to quantify...
Although once we've determined the best morale/training countries we can compare key units that we're interested in and rank them because it will be easier once specific countries have been indentified...
* grabs popcorn and sits down to watch *
T_R