If I may use the thread to depict my own preferences for a Rococo-like game
(please, one or two more votes to make Rococo eligible for the Game
Courier tournament, it is at least as interesting as Ultima), I would keep
the Cannon Pawns, which are a significant amelioration against the
Immobilizer, also with their non-capturing jump, but on an 81+40-square
board which would weaken them a bit. (It looks too big, but the outer
squares seldom carry more than one or two pieces.) I would retain only one
Long Leaper (the outer squares make two Long-Leapers too strong), and I
would bring back the Coordinator and introduce a new piece.
(I am thinking of the Bureaucrat, which would move as a non-capturing
Queen, but would also be able to turn as a move an enemy adjacent (or
perhaps a Knight's move away) piece into an already captured piece (not a
Pawn). In case it would act on adjacent pieces, either it wouldn't be
able to act on the Immobilizer or the Immobilizer wouldn't be able to
immobilize it, which is why having the Bureaucrat acting at the distance
of a Knight's move might be best.)
I am also thinking of pitting them on a 91+36-square hexagonal board, with
all the major pieces moving as hexagonal Rooks, but there the Cannon Pawns
might promote too easily, so allowing only a non-capturing move on a
side-adjacent piece or a capturing jump should be best.