If the Caliph and Cardinal were equally strong in other respects, it would not matter much whether you had one or the other. As in >95% of the cases you would still have some Pawns as well, which provide the mating potential. As it is the Cardinal is far more effective than the Caliph in destroying Pawns and Pawn chains. Which is far more important than the can-mate property.
To allow (help) mates with K+piece on a rectangular board the piece needs to be able to check two orthogonally adjacent squares. That implies it cannot be color bound or color alternating, but it is a stronger limitation than that: a BH or WA would be neither, but cannot cause help mates. Even if help mates are possible, it might not be possible to force a mate in general. Either because the piece is so weak that you cannot even drive the bare King into a corner, or because of a tactical peculiarity (such as with the quite strong Wildebeest, NC). The weakest piece I could find that still can force mate on 8x8 was the Deva (and its mirror image): lbfFrW, a sobset of the King, with only 5 move targets.
Btw, limitations of a drawing tool can never be a excuse for poor graphics; there exist plenty of tools without any limitations.
If the Caliph and Cardinal were equally strong in other respects, it would not matter much whether you had one or the other. As in >95% of the cases you would still have some Pawns as well, which provide the mating potential. As it is the Cardinal is far more effective than the Caliph in destroying Pawns and Pawn chains. Which is far more important than the can-mate property.
To allow (help) mates with K+piece on a rectangular board the piece needs to be able to check two orthogonally adjacent squares. That implies it cannot be color bound or color alternating, but it is a stronger limitation than that: a BH or WA would be neither, but cannot cause help mates. Even if help mates are possible, it might not be possible to force a mate in general. Either because the piece is so weak that you cannot even drive the bare King into a corner, or because of a tactical peculiarity (such as with the quite strong Wildebeest, NC). The weakest piece I could find that still can force mate on 8x8 was the Deva (and its mirror image): lbfFrW, a sobset of the King, with only 5 move targets.
Btw, limitations of a drawing tool can never be a excuse for poor graphics; there exist plenty of tools without any limitations.