Thermopylae Green king sac

What's up with Thermopylae chess having the odd rule that if the green king gets captured by the blue checker, then the green wins?

Am I the only one who gets annoyed to be in the middle of a game of Thermopylae and close to the end, green runs his king to the blue checker to force it to capture them, and then I lose just because they lost their king to not me?

I believe that this rule reflects the historical fact that the Spartans, representing the greens was led by King Leonidas I, who died in battle. His death served as a martyr and galvanized the Greeks to beat back the Persians. I suppose this rule is to honor him.

But how does the AI work from blue?

Blue is F-checker, which play 'futer' check moves. If it doesn't have a check move, it will play the best move instead!
Thus, blue will try not to capture green's royal general, but if it does not have any check, then blue rook captures green royal general(if available) and green wins.
P.S: blue can be 'trapped' in checking yellow.

I think it's to generate balance between two players because red is too powerful.

This feature can be made by FEN4.