Perhaps the test would be fairer to the Romans if you were fighting a unit with more armour. The pila have a large advantage of being AP, but that counts for nothing against Lugoae. You should instead match the Cohors Reformata and Gaeoras against an armoured late-game infantry unit, instead of the Lugoae with are, anyways, not a unit that Post-Marian Romans should really be fighting. Too low-level...