I never measured the Steward, but I have little doubt that its value is similar to that of Ferz and Wazir. (Which already are almost indistinguishable, about 1.5 Pawn or slightly less.) A Wazir behind a wall of Pawns tested as 25cP worse than in or before it, like other orthogonal movers. (But because the value is so small to begin with it is more noticeable.) I suppose this has to do with the difficulty of developing it, and thus suppose a Steward would have that too.
Note that a pair of Stewards can in general force checkmate against a bare King, while a pair of Ferzes or Wazirs cannot (and the mixed pair only very rarely, even though it can take very many moves then).
I never measured the Steward, but I have little doubt that its value is similar to that of Ferz and Wazir. (Which already are almost indistinguishable, about 1.5 Pawn or slightly less.) A Wazir behind a wall of Pawns tested as 25cP worse than in or before it, like other orthogonal movers. (But because the value is so small to begin with it is more noticeable.) I suppose this has to do with the difficulty of developing it, and thus suppose a Steward would have that too.
Note that a pair of Stewards can in general force checkmate against a bare King, while a pair of Ferzes or Wazirs cannot (and the mixed pair only very rarely, even though it can take very many moves then).