Would a "Can train Cavalry Archer in Feudal Age" Civ be too overpowered?
I think getting things one age earlier is a pretty unique concept, and has only been done with Hand Cannoneers as far as I know. Cav Archers are potentially the best unit for something like this since they normally rely pretty heavily on both Castle Age blacksmith upgrades and stable techs. They'd probably need some stat nerfs while in Feudal but I can see it being a really interesting alternative to standard Feudal play.
Is this a feasible concept by any means?