Simmy does a poor job of managing a team when you fill out the rosters. I can't imagine a team where Simmy fills out the roster. HBD just has too many moving parts. Simmy doing arbs is a good example. 70% of the demand. That's how detailed it is. Imagine FA signings, trades, playing time allocation, etc, etc.
The "solution" is to allow "traveling teams". Users actually "own" the team and can place them in worlds that will accept them. Let them carry the 40 man(which means they would be placing recent draftees/IFA signings on their 40 but that's the breaks) from world to world.
This will, in fact, never happen but it would solve the problem. I wouldn't let them in my worlds but I bet a lot of commissioners sitting on 9 openings would. I imagine the long-term effect would be horrible so some player generation adjustments would have to be made.