I don't think slow training is something that is to be "fixed". It's more like a feature - one that decently mimics the real world. I don't believe there was ever a great warrior who was only a peasant a year before. Training takes years both IRL and in DF. And like in RL, getting real combat experience counts for more than spending your days watching dodging demonstrations and lightly tapping your friends with the weapon of choice and getting lightly tapped by them.A few forts ago I had a low level fighter who was one of sole 3 survivors of 30 original military dwarves. Due to incredible experience gained in that siege, he got legendary status in knife user and soon became legendary in dodge, armor user, and shield user as well. So it's really not that much of that problem getting your dwarves experienced, as long as it is not by locking them in a nice sterile environment of the barracks.