anyjah and taylorc, the MK 22 capsule wasn't designed for any one exclusive stereo setup. The stereo bar which Schoeps sells for that capsule (the "STC 22") was designed so that the pickup angle--what Dr. Michael Williams calls the "stereophonic recording angle"--would be similar to that of a real ORTF arrangement. But of course there is nothing sacred about that particular stereophonic recording angle. You always need to match the pickup angle of your setup to the geometry of the recording venue, and sometimes that calls for wider pickup angles while other times it calls for narrower ones.
By making the capsules closer together you would increase the stereophonic recording angle--or in other words, in playback, the stereo image will seem somewhat narrower than it would have been with the capsules farther apart. So it would be good if you could move the microphones proportionally a little closer to the sound sources than you would have done if they had been spread farther apart.
I have the "Williams chart" which the engineers at Schoeps worked out for the MK 22; if I'm reading it correctly, it says that the stereophonic recording angle for the recommended 21 cm distance with 110° between axes would be nearly ±50°, while for a 17 cm distance between capsules the angle would widen about 6° on either side of the center line. But I'd like to double-check those figures--I'll post a P.S. to this message one way or the other as soon as I've had a chance to do so.
--best regards
