Historians are perhaps some of the worst futurists. If there's anything you learn about the past, it's that it does not teach you lessons about the modern world. People don't really learn from the past and do "better", because they're confronted with different situations than obtained back in the day. That old Santayana quote is nonsense because if you draw anything more than a superficial understanding of much of anything from history, the "lessons" you might learn are very difficult to apply, and sometimes contradictory in their messages.
When you characterize the "ages" of the past (I'm not entirely sure what your criteria are there, in your particular case), no matter how you do it, your periodization is going to be flawed in some way. No way around it, really, except to alter the periods' definitions so far as to become practically useless. That doesn't make periodization in itself useless; it's a convenient shorthand. It's not something you can then turn around and use to prove some kind of natural progression.
When you characterize the "ages" of the past (I'm not entirely sure what your criteria are there, in your particular case), no matter how you do it, your periodization is going to be flawed in some way. No way around it, really, except to alter the periods' definitions so far as to become practically useless. That doesn't make periodization in itself useless; it's a convenient shorthand. It's not something you can then turn around and use to prove some kind of natural progression.