It had been a while since I read through the Gnostic texts, it can be interesting but complicated for me read about. The list seems like a very natural kind of extension of what Christianity might have turned into, it some ways, had it not been reduced in the pan. The text that I most recently looked at, was the Pistis-Sophia, which was a rather densely mind-blowing read. I couldn't absorb much at a first pass. It seemed that every passage featured new layers, new spiritual dimensions and organizations of entities
I think there are many individual Gnostic texts that, on their own, could give rise to an entire practice and a rich one.
Interestingly, Gnostic practices have ties to proto-Orthodox monasticism, and gnostic practices are still mentioned in some Orthodox manuscripts.
In particular, they mention how the Gnostics viewed the gnosis gained during hesychasm as salvific on its own and how the hesychasm was performed without an accompanying prayer, which would later cause the Quietists to face accusations of resurrecting Gnosticism.
Quietism is probably quite similar to the practices of the Sethians, at least, although "Gnostic" became a very general term later on and I doubt that later gnostics such as the Bogomils engaged in the same sort of mysticism.
Some of the works of Zosimos of Panopolis, who was speculated to be a Sethian, also seem to give us a window into what early Gnostic mysticism looked like. If you're looking to understand the Gnostic texts, I think the most accurate approach is with an understanding of its roots in Neoplatonism alongside these ties to mysticism, at least in my opinion.
From that place of understanding, the specific names, orders, and numbers of the spirits might not actually be so important to the practice. They work more to form a sort of conceptual ladder for the initiate to climb until they reach epiphanic insight about their own oneness with the cosmos.
Reaching that insight honestly only takes a couple of years, but it takes disciplined practice and constant meditation to maintain. It can be a sort of laborious process. I abandoned it when I came to believe that it's merely an altered state of consciousness, dismissing its transcendental properties to focus on what I consider to be "real" issues: i.e., material issues. If I could still suspend my disbelief in the supernatural, I would probably have remained in that state of spiritual purity until my death with the belief that I would return to the One with the shedding of my body.
Of course, my approach to Gnosticism is, like most these days, idiosyncratic. I just hope this provides a worthwhile perspective to consider when understanding these Gnostic hierarchies.