> It's kind of funny to picture the kings racing across the board to capture or reactivate the last inert queen.
That would never happen. Because of the “of either color” clause, a king can’t even move to a square adjacent to a queen of the other color, as that activates the queen, moving the king into check.
Also, if the kings are included in the “piece” category of “a piece may only move if it is adjacent to another piece of either color” (which, I think/guess the OP didn’t consider), a lone king cannot race across the board.
That would never happen. Because of the “of either color” clause, a king can’t even move to a square adjacent to a queen of the other color, as that activates the queen, moving the king into check.
Also, if the kings are included in the “piece” category of “a piece may only move if it is adjacent to another piece of either color” (which, I think/guess the OP didn’t consider), a lone king cannot race across the board.