I group Levee and Kashmir together too. Heavy, dark, otherworldly, repetitive in a good way cathartic dirges with especially great drums.
I group other Zep songs together too although I’d need to think about it some to define the groups. Off the top of my head I see Since I’ve Been Loving You and I’m Gonna Crawl in a similar way, sort of enhanced blues songs with sophisticated progressions and great solos.
Hot Dog and Gallows Pole would probably go in the annoying list. There are a few others that are repetitive *not* in a good way that wind up dragging on a bit...In My Time Of Dying comes to mind.
Overall I see most Zep albums almost as mini greatest hits albums, each with its own flavor and very little filler.
perfect analysis, tks!