Moving thread to the EB submod forum

Yes, it's possible to generate an army via a script. Check out Hax's civil war guide for details. Unfortunately, this army can only consist of units that the owning faction can recruit. Since all high-end Roman units are unique to Rome, you cannot use these in the "rebel" armies.

(You could modify the EDU file to assign the Roman units to the "Spartacus" faction, but that may result in model-sharing conflicts, so I am not sure this will work.)