What Nikon Delivers

 D7500, AF-S Nikkor 10-20mm VR G DX

And what do I get if I stay with Nikon.

1. Maintaining my investment. I own a fair bit of glass today, mostly manual focus lenses of various sorts, but also a small but solid set of AF F mount lenses - The 10-20VR, Tamron 17-50/2.8, 24-85VF, 85/1.8G, Tamron 90mm f2.8 macro, 80-400G and 300/4D. All but one, the Tamron 90mm, AF on all 3 bodies, with my D7500 supporting the screwdriver AF lens just fine. And of course my two lonely Z AF primes, the 28/2.8 SE and 40/2 SE. And of course I have 3 bodies (2 Z, 1 F mount) that all work pretty well for me. I would need to sell at least some of the glass to make this transition work (although Fuji does have a decent AF-S compatible AF adapter from Fringer that could let me continue to leverage my AF-S collection)

2. Easy path back to FX. In fact I'd never really have left FX behind as I've still got the Z7 and this keeps a mostly full FX lens kit for me (both manual and AF lenses). I can operate as wholly DX, wholly FX or a mix depending on which gear I put in the bag. 

3. Incredibly broad adaptation options, including AF adapters for Fuji X and Sony E mounts. This is the real kicker. Is the answer to my desire for access to Fuji's lens line simply shooting Fuji mount lenses on Z?

4. A path to possibly making my 10,000 images in one system goal, as well as my general 'Stop Chasing the Dragon' dream. The latter is probably the more important aspect. 

5. Blues. Those Nikon blues that I love and Fuji can't really deliver due to a combination of their general colour rendering choices plus XTrans's natural weakness in rendering blues vs greens. 

To be honest, I keep going around in circles. Fuji gets me direct access to higher-end APS-C bodies and a broader lens line, Nikon has better PASM body options (I can get a used Z8 for not much more than new X-H2(s) money and the Z8 stomps the X-H2s as an APS-C performance body and the X-H2 as a resolution body). Nikon plays into my current investment, lets me play with DSLR's and F mount lenses and I can add adapters for Fuji and Sony both. 

That brings me around to the question of if I do stay on course for once, where do I go?

My biggest weaknesses right now are in native UWA options in Z mount, I only really have 2 UWA options in the bag, the ZF 21/2.8 and the 10-20VR, and they are both F mount lenses (1 each of FX and DX). I'm leaning here to getting the Viltrox 14/4, which would give me a very wide & compact UWA for the Z7 and a native 21mm equivalent for the Zfc, then adding a 9/10mm, likely one of the 7Artisans offerings, for the Zfc. Has to be primes if I want native and reasonably priced, although the 14-30 is always an option at a notable cost increase. 

After that, I need to fill the gaps on the Zfc's lens lineup. The 35/1.4 and 55/1.4 work well, but the 25/2 doesn't handle as well and I'm still facing a gap between 25mm and 14mm here. TTArtisan 17/1.4 is probably the answer. I really do wish somebody did a good fast 22-26mm manual prime though, may end up with an AF lens in this slot. Then the long end, I'm looking at the 7Artisans 75/2 (compact, useful on both Z bodies, inexpensive and pretty good, plus not a direct conflict with my 85/1.8G) and their 60mm macro (gives me a native DX macro option for the Zfc). 

In terms of zooms, I may grab an inexpensive FX UWA (likely the 18-35G or 16-35VR) in F mount to round out the Z7 adapted kit. Then it would be looking at DX Z zooms, likely the 16-50/2.8 + 70-180/2.8 combo.

On the Z7 side, I could also simply get a Z 24-200 so I have a truly compact hiking kit with that lens and the 14/4.