Is your feature request related to a problem? Please describe.
I want to be able to set up trading halls and retain some vanilla villagers because of their squidlike skins and level of stupidity to be slaves.

Describe the solution you'd like
I do not wish to overhaul all the villagers, just a certain % generated in the world where that % can be configurable in the config file

Describe alternatives you've considered
so if there is 2 village, and the overhaul rate is set to 50% of the world, then only 1 village should be overhauled to MCA Reborn while the other village remains the same vanilla for me to use for my redstone contraption slavery.

Additional context
Add any other context or screenshots about the feature request here.

fractionOfVanillaVillages in the config :)
https://github.com/Luke100000/minecraft-comes-alive/wiki/Config