Quote Originally Posted by pezhetairoi
Praetorian cohorts are available for training as long as you have an imperial palace, marian reforms or not. Urbans are also available without Marian reforms, according to the export_descr_buildings text file.
I guess you are using 1.0/1.1 then.
Before patch there were several other units that looked "universaly" available like urbans, but they were never available before reforms since imperial palace triggered the reforms.

But since patch chnaged reforms not to happed immediatly after getting imperial palace, so developer team modified those units availabe after marius only. They only missed praetorians, I guess because they were trainable in palace and not barracks (easy to miss).