Definetly. Go with the idea.
There have been efforts at creating another age.
My chaos maps such as "Poke in the Eye"
http://www.dom3minions.com/downloads.htm
I refer to as being Age Zero or Pre-Early Age. When thousands of pretenders roamed the planet still trying to settle into specific nations. Total insanity.
There are various MODs which create Age 4 nations. Ulm gone techno, Nations of Knights, Samurai, Jewish, American Indian, etc. It might be fun to incorporate a bunch of them together, fix any conflicts in ID numbers, and create a 4th age mod that puts them all into the game along the line of the "11 Nations" mod.