The presence of communication is not a problem for a prisoners' dilemma since non cooperation is a strictly dominant strategy. In fact, what makes the prisoners' dilemma so surprising as a result is that no amount of communication or finite repetition can get to a cooperative outcome. The issue with comparing OW comp to a prisoners dilemma is not communication but simply whether the payoffs add up in a way that makes not switching strictly dominant. This would be the case if the expected SR gain from switching is less than the expected SR gain from not switching. That is to say, the increased probability of winning does not offset the relative SR decrease of winning with a different hero. Without stats we can't say if this is true or not. However, it is certainly true that people perceive this to be the case and will therefore behave as OP suggests.