Maybe to 107 BC when Marius reformed the Army? Then we would have another mod covering the time of the late republic and the rebellions?
No,no and no...That is bad.The one mod idea is far better then this one.

They have so much ways to screw every thing in the mod
Then all the hard work we have done would be in vain.I do not no the "core" of the game so go,because I am not that good at scripting.In this case I would rather listen to a person who has some,hameleona,or I would go and ask the other mod leaders how did they do it and what are the effects.

However,I am rather for Celt-Iberians then free people,but do as you think it should be best.