Not necessarily. MOCs don’t have to be set in stone (nothing does, for that matter) and you can create them as you need them. For example, since I want to write a novel, a lot of notes I take are writing tips and quotes from authors. So when I first started taking notes on that topic, I made a new page just called “Writing Tips” that started out empty, but as I take notes I add them to it. But while I was taking notes on writing, I thought of a cool idea for a story. So I created a new MOC page called “Story Ideas” and put a link there to the note with my cool new idea. After a few weeks I noticed my “Story Ideas” was getting cluttered with a whole bunch of random ideas that could be completely unrelated, so I decided to make new MOC pages to organize them. So for example, I have a page for Plot Ideas, a page for Character Ideas, a page for Setting Ideas, etc. So my “Story Ideas” MOC turned into a hub that branches out into more specific MOC pages as I need them.
All of that is just to say, a cool aspect of Obsidian is that it can grow and change as you need it to. Just this morning I spent like ten minutes changing my Daily Notes Template because I thought of an idea that might make it work better for me. It was good before, but it’s better now. It’s kind of tough to get into that mindset, at least for me, but I’m learning that my vault is super flexible and I can mold it into whatever I need it to be. And if my needs change, my vault can change again.
I wouldn’t say “those connections are supposed to naturally recur to you.” Instead, I’d say your vault needs to be set up however works best for the way you think. I’ve heard it referred to as “Friction”: if something about your vault causes “friction” while you work, meaning there’s something getting in the way and slowing you down, then see if you can change it to lessen the friction. That’s why I changed up my Daily Notes Template earlier today, I noticed something that was working okay but not optimal, so I fixed it up to make it work better, which allows me to work easier. So if making links as you go along doesn’t work for you, you don’t have to do that! Maybe instead you need to push the “New Note” button and write down the other idea you had, then come back to the original note and link it later. Or maybe you need to have multiple notes open at once so you can flesh out one note, and use the second note as a “catch-all” note where you write the random thoughts that pop into your head to sort later. Or maybe you need to keep some Post-It notes at your desk. Whatever works for you, and you don’t have to stick with just one method either. For example, some days I use my Daily Note a ton, keeping track of all my tasks and journal about what happens to me during the day. Other days, I don’t touch my daily note because my tasks for the day are in my head and I forget to journal. Neither is wrong, it’s just what I needed that day.
I would say if you want to build two vaults to see what works best for you, that’s absolutely a valid option. I had several vaults before I settled on my current setup. I would caution you that it can be tough trying to keep track of info in multiple locations, so you might want to use the two vaults for separate topics (one for work and one personal, for example) or figure out a way to ensure the information gets both places easily. Since notes are just text files, you could go into your Obsidian folder on you hard drive and just copy/paste notes from one vault into the other. This is tough to sustain though, and ultimately just creates more work for you so I’d be careful how you use the two vaults.