I'll respond to your partial cross-post with one of my own!
Yes we'll definitely have default training available (as a matter of fact, I know from your email of last night that you've already put it in ). And things like training depending on cost-effectiveness can be easily handled using a return-on-investment parameter just like much of the econ stuff uses. Essentially where training is cheaper per unit (due to training infra) more training will (or at least probably should) be done. The thing that will require a little extra effort is the idea of rotating troops thru the training facilities. But we can sure do something reasonable, if not optimal, on that front too. Perhaps letting there be just one training center per province that automatically supports training there is one way to do it.
Now building the best amount of training facilities will be a tough decision also, but I think we can get a decent solution when we're further along.