Just wondering if someone could perhaps add a couple more Socii units for Rome to recruit.

The vanilla game gives you Socii Hastati, Socii Equites, and Extrordinarii versions of the two.

From my readings/research the Socii Alae (Italian allied armies) were apparently very similar if not total copies of the Roman manipular legion in regards to their weapons, armor, and unit types. The only difference was of coarse that the Legion was made up of Roman citizens and the Socii were men from the allied Italian city-states.

More-or-less what I'm looking for is the addition of:

Socii Principes
Socii Triarii
Socii Velites

Also, if someone wants to take it that far they could also add in Socii versions of some naval units as well since allied coastal cities did provide "socii navales".