DSatz says (as usual, in far too many words) that he personally prefers selected, matched pairs of capsules for stereo recording with coincident or closely-spaced microphones. DSatz says that for more widely spaced microphones or for the kind of spot or solo miking that's done in most studio recording, it hardly matters.
DSatz says that even with closely-spaced pairs, where you place your microphones is more important than the last fraction of a dB of matching. Also that it's good if you connect the microphones to a recorder of some kind, and remember to turn the recorder on before the music starts. DSatz says that even a mediocre recording of a good musical performance is worth far more than a great recording of music that says nothing.
DSatz says put your hands on your hips. DSatz says put your hands on your head ...
--best regards
P.S.: If you can get the serial numbers of the capsules, you can write to mailbox@schoeps.de, and they'll tell you from their records how close a match they are (or were when they were produced). Of course with cardioids your main application would probably be closely-spaced rather than coincident recording anyway, or at least DSatz would hope so, unless you really need the mono compatibility.