My notes are at least influenced by zettelkasten, if not yet a proper zettelkasten. I hope to get there eventually, but I’m definitely in early days.
I think, in your described case, MOCs can be helpful. For me, it’s a pretty natural development. There are just natural levels of my field I want to take notes on, but still broad categories. There are definitely connections between areas (medications for different uses/disease treatments is a great example), but definitely clear hierarchical groups. I’m not even sure I had an understanding of MOC’s when I started making what I’m making, and I would definitely say that my MOCs don’t have overarching notes and summaries and ideas in them, but, for what I’m building, that’s fine.
I’m creating a reference framework for articles I want to remember or at least to have key ideas when I’m thinking about things. I discovered I kept saving the same articles when a clinical question came up. As I build my system, I’ve started to alleviate that problem (still incorporating articles I’ve collected over the years and new ones).
Overtime, I have no doubt the system I have will evolve, particularly pulling more random ideas of my own together and integrating them into all these reference notes.
Hope that helps.