The Nady is about 2.5" wide at the external diameter of the ring. No idea of how wide the schoeps one is.
All the Schoeps A20s I have here are exactly 2" external diameter, 1.5" internal diameter.
The mic holders are designed to hold mics which are 20mm in diameter. At a push, they will stretch to 21mm but the plastic is fairly brittle and I've snapped several by fitting my newer KM100 (21mm) bodies into them (my older KM100s are 20mm - no idea why Neumann changed this!).
They'll also take full size DPA 4000 series mics (though not the 4041) if I wrap a few turns of gaffer (duck) tape around the mics where they sit in the mount. You do however have to use the "S"version of the A20, as the extra length/weight of the DPAs needs stiffer elastic to support them without them sagging. In the standard elastics they flop about, making them difficult to point and at some angles the inside mount can touch the outer ring making the whole exercise a little pointless.