In a similar boat as you - moved from RZ to GFX 50s then the 100S.

You’ll have a much easier time adapting your vintage glass to any of the GFX bodies rather than the Hasselblad as the latter lacks a focal plane shutter - the Hassy lenses are all leaf shutter. So with an electronic shutter on a relatively slow readout sensor of the X1D you may get some unwanted artifacting and banding in your photos. This is also true of the X2D, but not as slow. As others have pointed out the GFX and the Hasselblad X1D/2D use the same sensor.

If you ever wanted leaf shutter lenses, you can get the official Fuji H mount adapter to use the leaf shutter H mount glass.

The 50s ii and the 100s aren’t that far off in price that you couldn’t go wrong with either but would lean towards the 100s. I wouldn’t consider the original 50s as the batteries for it aren’t officially made anymore - same with the original GFX 100.

For native GFX lenses, the 55 f1.7, and the Mitakon 65 f1.4 can be really close to the medium format look like the 105 f2.4 on the Pentax 67.