Stacking 2 24" monitors versus just using a 48" 4K display would actually be worse on your neck you have added bezel space. There is also no such thing as a too much vertical you can scale the resolution however you like it's not complicated. If you set the monitors back a little further you won't need to crane your neck as much either. It's also worth noting a 4K display can run 2.76:1 aspect ratio at 4096x1484 or 4080x1478 in place of it's standard resolution and aspect ratio for either improved performance or simply because it looks way more cinematic I mean ultra panavision 70 sure why not!? Seems legit!Poorly designed or not, most games are Hor+ and don't let you control the vertical FOV at all.
The large 4k monitor (43-55") seems to work for some people, but for me, it's too vertical and having to look up is hard on my neck. I've been thinking I may have made a mistake by adding a top monitor because anything above my 3 main 24" monitors (top of the screens are eye level) is hard on my neck. I have a very high amount of correction in my glasses and small lenses, so I can't really look up with just my eyes, I have to lift my head so for me, too much vertical is bad bad bad.
I almost went with a single 34" ultrawide for simplicity and I probably would have except using 3 1440P monitors really helps me in my work.