I made this simple geometry node setup that can create scifi-ish greebles/structures.
I take a set of pre made models and then distribute them on a cube, and mirrors them.
(image not made by me, but uses my project)
Some of the base models:
Some examples of the generated structures:
You can download the blend file for free here: https://mart0nnn.gumroad.com/l/scifigreebles