In Niklas Luhmann’s zettelkasten (the godfather of zettlekasten) sequenced notes were based on numbering. So if your note is numbered 1, and you create a new one on the basis of the 1st one, it could be numbered 1A. Another note created on the basis of 1 could be numbered 1B.
A note created on the basis of 1A could be numbered 1A1, and so on. Luhmann did not have a digital system, he had physical index card in a drawer set, i.e. zettels in a zettelkasten.
The jury is out on whether a sequenced note system is useful in a dogotal set-up: some people swear by it, others believe it’s a waste of time.
I believe Luhmann’s reason for his numbered sequence system was to be able to discover unexpected paths towards new ideas, but also to find his way around his zettelkasten, comparable to what we now call “search”. Our digital systems allow us quick, very specific, very detailed searches, more than he could only dream of.
Moreover, our linking system also allows us to wander from link to link and have our serendipity that way.
So, sequenced notes the Luhamann way? You’ll have to decide for yourself.
Bottom line: there is no generally right or wrong system. The only right system is the one that works for you, which depends on what your objectives are.