In the case of the Rangers, it does not translate to success, but it does translate to long-term viability. The Senators or Sabres cannot survive as many seasons of failure as the big-market US teams.
In the case of MLB, it should be the same. People point to the salary caps in the NFL and NBA, but it's really the revenue sharing (their local broadcast revenue is a pittance, except for the Knicks, Nets and Lakers).
But the point about socialism is that you have to recognize that a sports league is a single enterprise with franchises. In terms of revenue, the teams do not compete against each other.
Agreed. Revenue sharing or spending limits > salary cap