The key to style guides is to not have so many rules. Agree on the number of spacing and where to put braces. Past that, it’s obsessing on form over function, which you cannot control simply by virtue of having many people work together on the same codebase.
You should worry more about how things are named, the number of abstractions used, and whether the code has any comments explaining the writer’s intent.
This is broadly what reasonable people believe, but there are crazy people who WILL obsess over form and nitpick your whitespaces or other trivial bullshit if given a chance. An authoritative style guide shuts down many such detours.
It's not even just about obsessive nitpicking. There are people who, for example, prefer code with spaces around the parens for conditions and people who don't. If there's no enforced style guide and one from each camp end up touching the same code, you're likely to get a bunch of pointless noise in the diffs. Even if no one is going to hold up a diff arguing over it, it makes it harder to review changes.
I think you can have as many rules as you want as long as there's something like black or rustfmt, just a script you run that auto-formats your code. You never have to worry about the rules because there is no configuration thus nothing to argue about. Sometimes your code gets formatted weird but who cares, just do your work.
You should worry more about how things are named, the number of abstractions used, and whether the code has any comments explaining the writer’s intent.