I've now coded in the Marian Reform. It is based on the RTR-VII script, but with changes, recognising the different needs of my map.
The Marian Reform should basically remove the Roman hastati, principes and triarii, and replace them with a single (stronger) legionary unit. As a side effect, equites will no longer be recruitable, as they fell into disuse (foreign cavalry units were favoured).
The conditions are the following:
-Have at least three huge cities in Italy
-Complete a certain amount of territorial expansion, as illuminated by this map:
Basically, fourteen territorial "points" are required. A point is obtained by capturing the amount of settlements in an area as the numbers on the map indicate for that region. Italy counts as three points, and the others highlighted count two. This means that, should you capture those areas, you will only need to conquer three other areas. Thus, a recreation of the historical Empire during the Republic will trigger the reforms, but so will deviations from it, should you, say, feel the urge to head for Germania, Gaul and Britain, or maybe take Egypt early.
This will be released in the next patch I just need to finish some work on the government system, which will hopefully help the economic situation, and balance some Greek units