Quote Originally Posted by solypsist
it would be great if lower-tier units were no longer available after a certain period of time once the advanced units appeared.

The pre marian units are not longer avaible for training or rebuilding after the reforms what what you want appears to already be there...

Perhapes there should be a period (as you suggest) where only the early cohorts are available and then the others added or their name should be changed to "cheap legionaires" or something similar (but cooler)....

I personally go to the trouble of disbanding a pre marian unit when a build a post marian unit in a city as it helps keep the pop figure up...