Why couldn't 2sm and Triple M both get the rights?
Different bands, hence different markets.
However if it came down to 1 station, I would have to go MMM as they have a greater market share over 2sm and therefore will get more exposure for League.
You can be sure though that 2GB will state that they get 1st choice of the call of the game of the round. Surely that will be in their contracts.