Well, if you want some advice:

I would suggest: GO LARGE!

1.) The Huge setting might drain population really quickly, units would cost more and you would probably have fewer large troops instead of many smaller ones.

2.) 80 is quite close to 100, a century...

3.) You still have room for maneuver. With Huge units, you have no room in cities. And in the open a size 3-4 line can span whole gaps between trees or hills.