Well I checked through the files and all the Sicily regions definitely count.

When the reforms come about, I usually use it as a chance to retire my veterans or have them on standby in an area to take on rebels. Once you have enough legionaries to replace your Principes and Hastati it's nice to reward your loyal troops with some much needed rest. Any true veterans (6+ experience) can be sent to the capital as honourary guards to your leader. Sure it's a bit of a nuisance to lose your existing army structure, but that's the price for progress!


By the way, you could always edit the export_descr_buildings.txt file and change it so the Hastati, Principes etc can be built all the time, or even swap the recruitment requirements for pre-Marian units so they can be trained during the Marian reforms, and the Post-Marian units so they can only be trained before the reforms. If you do that now, you're stuck with the old units and can't train the new ones, and then you can always the edit the file again back to how it was before when you decide the reforms should occur. It's a minor effort really, but worth considering. Of course all generals will remain upgraded unless you change that too.