That's basically what I do. 24" 4K in the middle and 2 17" eizos beside it. They're 1280x1024 though so I have 200% scaling in the middle and 100% at the sides. This causes some OS issues in FreeBSD (I mitigate with xrandr) and Windows which is still screwy to this day. On Mac it works perfectly but I don't use Mac much anymore.