Have you considered allowing drafting units with any of the ancient civics in the scenario? Because we could use the rebellion units setup for this also - I just realized there is a getConscriptUnit callback in CvGameUtils... So drafting units wouldn't cause any Explorers to appear in a pre-gunpowder era. 
Or we could have archery units as the conscript units instead of the default (pre-gunpowder) melee units. On a whole I think drafting would give the scenario a whole new dynamic; the potential for bigger armies - and more wars.

Or we could have archery units as the conscript units instead of the default (pre-gunpowder) melee units. On a whole I think drafting would give the scenario a whole new dynamic; the potential for bigger armies - and more wars.

I just remember there is a version 2 series for JRM
) can use a renamed pictish rebels and I think they live in the pict's slot, so only one new power will need to be made 

Because there would be two in the case of the Hellenic Rebels. So this would probably require some rewrites - but better to get those in now than later.
so I'm not sure... it seems like a good idea that you get militia but the rebels themselves should get powerful units. Another idea would be that conscripted units get a promotion which makes them weaker than standard say... Conscripted - -10% str available to the late game conscripts (eg the ones which would be harder to train in real life...archers, spears and swordsman are not that hard to train so don't get this promotion)