Historical with fictional minors
 

I want to create a historical league in the 1940's. I want full minors populated with mostly fictional players but including a mix of future and end-of-career major leaguers. I will block fictional players from reaching the majors. Should I adjust the player creation settings to a lower figure to keep really good fictional players from dominating the high minors? If so, could someone suggest a setting? I would appreciate any other tips that you might have for this type of league.

The simplest way to accomplish this is to populate only the lowest level(s) minor leagues with fictional players. You may have to iterate this as the AI shifts some of them into higher levels to fill out rosters. With player development on, some fictionals will become legitimate stars at the higher levels, but perhaps in numbers that are OK with you.