Hmmm. Jarmans Idea has real merit, and is basically the same as Shogun2 with generic troops replenishing like ashigaru and anything else like samarai did. This is probably the simplest and most realistic fix. I'm not so sure the larger boost for higher tier units is even necessary, as the rates is S2 worked well without needing adjustment, but the adition of a 'neibouring barracks' calculator works well for me.

Back to my idea for a moment tho. The line is quite simple to me. For rome it's anything thats comes out of manipular barracks or any higher tier version of it. For all other factions the same is true in some way, Parthia has the noble line of recruitment buildings (elite) and the infantry line (Auxiliary). Pontus and all other greeks have the hoplite barracks chain (elite) and the peroikos line (auxiliary).

For barbarians it's a little less clear, but still works. The blacksmith line (Elite, includes balistae and chosen sword band ect) and the bronze-smith line (Auxiliary, includes sword band and spear band, but not chosen). Yes, this means that the balistae is considered elite for the barbarian factions only, but that works for me too. Siege engineers arn't exactly well known in the depths of germania.

So how about we merge the idea's? The units are still divided into elite and not, but instead of having to retrain them you have a major nerf to replenishment rate of elits unless the recruitment building is close? THe Auxiliaries and none-elites retrain at closer to current rates, meaning the armies can keep on trucking if they need to, but without the solid core uber-healing like they do now, and gradually retraining while in the arse end of the empire, but pumping troops out quickly while in the core provinces.