The distribution does not change at all. The variance increases. This is the main reason why an expansion was never done before. It fundamentally messes with the prior delicate balance. But it's so much fun to add new powers...
Keep in mind that the promo set was really intended to played by the Republic rules. The 2-card petition helps a lot at reducing the variance, although it doesn't solve the increased randomness of craftsman effectiveness.
I therefore salute the noble effort to find an alternate version of the game involving substitutions instead of additions!