I think this gets to the heart ...
They have rigid rules regarding the Single Entity nature (which frankly ... probably saved this league through some dark times) ... UNTIL they don't have rules. The MLS has a way of opening rules up to make things happen. I suspect this is just going to advance with more segregation of interests. The Toronto, NYCFC, LA, Seattle program (maybe others) will reach for more of a Global Branding and ... I believe ... that will lead the powers of MLS to be even more squishy.
And, what I didn't know, and it seems all my English friends do: The Salaries of the non-Stars is horribly low. The AAA tag on NYCFC is appropriate because lots of these guys are making a fraction of what the standard is in the EPL.
In MLS the pay disparity is pretty bleak.
Obafemi Martins gets paid 150k a game, and some guys get paid 35k a year.
It's the opening up of the rules that is the problem. If they can get a star player placed in a market, they'll rewrite the rules to make it happen. The league wanted Jermaine Jones in New England, despite the fact that Chicago had done all of the legwork to sign him and was willing to match the salary. So they orchestrate a "blind draw" which was certainly rigged.
The thing about Man City Junior is that people are forgetting that except for the 3 designated players (DPs), all of NYC FC's players will be owned by the league because of single entity.
Where things will could get really contentious is with NYC FC's Academy. If their Academy has a prospect that Man City desires, then they can just sign him up to the Man City Academy.
And it is time to end Single Entity.
Look at who owns MLS Clubs these days. This is not like it was in 1996 with Anschutz, Kraft and Lamar Hunt owning the entire league. You have Stan Kroenke, Anschutz, Cerner, City Group, Red Bull, Kraft etc.... MLS has absurdly strong owners.
Sporting Park and Red Bull Arena each cost 200 Million to build, and we have guys who get paid 50k a year playing in them
Single Entity had a role in the early days of the league for sure. Why would one Anschutz owned club object to anothe Anschutz owned club signing a player? But now all it does is suppress the market value of the player. It also keeps MLS from signing better talent below the DP level. MLS clubs have good talent in their first 5 players or so, but after that, the dropoff is pretty steep.