This is a good mod idea. I like it.
Nobody else has said this, and it needed to be said.
The problem that the mod was set up to solve is quite real, so it is good mod idea as such. As tragic as it is DizzyCrash set out to fix a problem that he/she did not understand the actual mechanics of, leading to the sub-par solution that is this mod. But I hate to see DizzyCrash be discouraged.
I dont see a setting in perfect world builder for historical character spawn rates, also i dont want to use a pocket world, i like makign it a continent of maximum size that I build and design from the ground up.
There is such a setting. It is called Population Limit and is set at 15000. That means that the game tries (and usually fails) to keep the historical population at 15000.
The main constraint is memory, you can set Population Limit to 100000 but my computer crashes if I set it so high. As I keep telling you, what matters is Population Limit against Site Cap.
There is no requirement to play a pocket world at all, it is just that if you cull your site cap on a large region then the region is going to be rather empty.
From what I gather you seem to want to play on a world with a few civilizations that have a large number of sites. That creates another problem because of these numbers in the entity files.
[MAX_STARTING_CIV_NUMBER:100]
[MAX_POP_NUMBER:10000]
[MAX_SITE_POP_NUMBER:120]
The first number is the total number of historical characters given to the civilization to start with, this is 100 which means a civilization gets 100 people, some of which will then marry and have babies, usually lots of them since there are plenty of historical slots for them to fill. The key thing is that this 100 have random traits but they are small enough to lead to a race forming.
The second number is the total number of historical characters that the civilization is allowed to have, normally it will not affect much since it is 2/3rds of the world limit. If you were however to have a large number of sites per civilization and a small number of civilizations, that is over 100 sites then it would cause a problem.
The third number is the total number of historical characters per site. This is the real diversity killer since it keeps a high historical character limit from actually being used. It is the reason why in the game I submitted there are still non-historical characters in the world despite there being the population limit for it.