I don't believe this outcome is optimal from an evolutionary standpoint. It requires the other player to know what your strategy is and accept the ultimatum (I will do x% better than you). The other player still has the option to reject the ultimatum, screwing over both parties.
In other words, for this strategy to work it needs "pragmatic" other players that are (a) intelligent enough to know what the other player is doing and (b) willing to accept the unequal outcome. This strategy isn't symmetric: if you turned two of these bots against each other the total outcome would be much worse than if two TFT bots played each other.
Thus it stands to reason that TFT or some small variant is still the evolutionary winner.
What I'm thinking is, it appears that players with a theory of mind may not actually use the optimal evolutionary strategy. Since humans have a theory of mind, my simulation may be a poor predictor of what my users would actually do.
In other words, for this strategy to work it needs "pragmatic" other players that are (a) intelligent enough to know what the other player is doing and (b) willing to accept the unequal outcome. This strategy isn't symmetric: if you turned two of these bots against each other the total outcome would be much worse than if two TFT bots played each other.
Thus it stands to reason that TFT or some small variant is still the evolutionary winner.