A guide or “advisor” offers suggestions/advice to best succeed with the most positive outcomes while reducing negative outcomes. You might still succeed on your own but you still want to hear all the possible options on the table, so you know what you have to work with and can make the best decision within your ability.
“This guide shows you how to “tank” on a shaman, but you need to do a bunch of other stuff to achieve this goal, all to still not even be close to a real tank spec/class.”
If you apply this same notion to warrior tank, then not following a warrior tank guide to the letter means you cannot tank. You only said this comment because of your natural fear that shaman tanking is hard and not following everything means failure. Therefore, you want to know everything that is at your disposal to alleviate your fear and succeed to the best of your capabilities, hence a guide.
Therefore, I ask again, where does it say you MUST do something? And I’d like to again point out, this sentence in the guide: “offer an ideal comp without overstepping”, “With the raid leader’s consent, suggest ideal Debuffs without overstepping.”.
Maybe the Wotlk Shaman Tank video guide is better? where it’s mentioned several more times: https://www.youtube.com/watch?v=u7gaBP8rqjg https://www.youtube.com/watch?v=dLGo493HQU8