What does everyone think of this concept of population growth affecting the size of the settlement?

It seems a little unbalanced, as growth can take ages and there seem very few ways to actually stimulate any serious booms that you may need, particularly on a frontier where it would very helpful to have the necessary military facilities quickly but can't due to insufficient population. Playing as the Julii I've taken over several Gaulish settlements, occupied and not killed anyone, and some 10 years on still haven't advanced at all even on low taxation. It seems a good idea, but would need tweaked in my opinion to give us more control over the growth rate.

What does everyone else think?