My EndeavourOS Arm setup was getting a little out of hand. So I built a Raspberry Pi 4b caddy to organize things. To save space with the USB SSDs, I set them into a dado and increased their vertical foot print, which exposes more surface area to the air, and which makes for a smaller horizontal foot print.
The RPi 4 and the extra micro SD card sit in recessed areas so they stay put.
Pudge