Your NUC is already running Linux since it is running ROCK but that is irrelevant anyway since you would be booting from the live media, performing your task and rebooting without the media when done. You would need a monitor and mouse (maybe keyboard too), however. I have a portable monitor I use for things like this.
Yes, I understand that the NUC is running a Linux ‘shell’. As you say the relevant aspect is the monitor and keyboard. It’s just easier to move 2 USB drives to another computer than connect a monitor and keyboard and mouse in my case.