Possible Solution to an Integrated Historical/Fictional Universe

[NYJuggalo45]

I'm not sure which forum (General Discussion or Historical Sim) this belongs in so I am posting it in both in hopes of feedback and thoughts. Any mods who want to delete/move this, feel free to.

What I have been unsuccessfully trying to set up is the following type of Universe:
- 1 Modern Day MLB w/ minors (and each level is lower talent ratings/player equiv)
- 2 Independant leagues (Japan & Cuba) w/o minors (lower than MLB but higher than AAA of MLB)
- 2 Winter leagues (between AA and A level)
The league would consist of a combination of historical and fictional players (up to this point everything is do-able). The impossible part comes when I would like the MLB and the 2 Independant leagues & 2 Winter leagues to share the same crop of historical players. Something where MLB gets the top 40% of talent, Japan/Cuba gets 20% each of middle of the road talent, and Winter leagues get 10% each of the career benchwarmers/minor leaguers, but who could be stars there. Unfortunately, it seems as this is not something that is possible, but in thinking about this while at work today I'm wondering if I might have an idea that could sort of replicate this and would like feedback.

Universe would consist of:
- 1 Modern Day MLB w/ only Rookie league A ball minors (A ball very low talent/player equiv)
- 1 Fairly big Independant league w/o minors (which would essentially be of AAA talent levels)
- 1 Fairly big Winter league (which would essentially be of AA talent levels)
- Set minors FA to a short time (say 3 yrs) so guys stuck in the MLB minors can bolt after 3 years without promotion to the bigs.
- Point the historical players to the MLB but allow FA's to sign with other leagues.

My hope here is that the true historical greats will be drafted by and spend their entire careers in the MLB, as well as the top of the crop of fictional players. The part-timers would decide they can make more money being a big fish in the Independant league than a backup in the MLB. And the historical bench warmers, who would be better than the lowest level of fictional players, would get tired of sitting in A ball minors and bolt for the Winter league after 3 yrs. My biggest concern is that the MLB minors would never develop as they only have A ball as a minor league system, but I'm hoping spending 3 yrs there, they would either be promoted to the MLB (which many historical players are right away since they come in with high skills from the draft) or move on to one of the other leagues and still be young enough to develop.

Thoughts? Possible? Incorrect thinking? Any input would be appreciated