Cincinnati-style Kriegspiel should be playable by different armies--the
rules specify that only pawn/piece is announced for a capture, not which
piece. The CWDA promotion rule needs to be modified to allow pawn
promotion only to pieces in one's own army--otherwise you would have to
know what army the other player is using to know your promotion choices.
(This weakens the Colorbound Clobberers a bit in the endgame--the CC's
often promote a pawn to the other side's Queen piece.)
Check announcements need consideration--what does the referee say if the
player is checked by a Camel? This is a Knightish type check, but not on
the same squares as would be indicated by 'check by Knight'. A check
from a Half-Duck three sqaures away may still be 'on the file', but the
player's legal moves are different than if the same check were by a Rook
or Queen (interposing is useless, but retreating on the file may work.)
Perhaps the best check announcement rule for KWDA is simply to announce
'check' with no directional indication.