Given that a lot of their failures are from fairly basic mistakes related to the unique setup (eg, thinking rather than defending immediately) I'd love to know how much they improve with basic tips.

Or possibly even whether they can learn from a game themselves. "Analyse your game for your failures" -> Then give a fresh agent of the same model that "learnings" doc for the next match. Do the rankings change over time, if models can write instructions for future selves?