yes there are basically 4 types of "male" units that can eco/fight.
You have your regular CS, same gather rates as vanilla (except a few new civ bonuses)
Then you have your Levied citizens (Perioikoi for sparta fall into this category even though they were citizens, they have a different label but same stats)
5% faster gather rates -10% dmg and -1.5 of hack/pierce resistance.
Then you have your serfs (mostly just stone throwers)
They gather 10% faster but do -15% less dmg and -5 range and 10% less accurate.
Lastly you have Helots (Slaves, really only sparta at moment and rome has a p3 swordslave)
they are 15% faster gather, but -20% less dmg, -5 range, 20% less accurate, less health....
Just opens up more ideas/strategies etc.