Well, King John was himself replaced by his infant son in 1216. Doesn't it
open the way to a calibrated number of (King-moving? Wazir-moving? Firz-
moving?) Princes, which could act as substitutes, instead of a Queen?
Maybe the French provinces call also for a second 4x4 (5x5?, 3x3x3?)
board, with a crossing of the Channel which would take a delay of two or
three turns...
(3x3x3 is of course debatable, even if it allows your Duke, but shouldn't
there be different laws regarding succession in England and in France?)