I agree - working backwards from the finale, Ahsoka has to be the main character; Maul the key villain, and Mandalore the key location. Arcs advancing the plot of those three are the “main story” of TCW, I suppose. Prior to the revival, it wasn’t as clear - maybe Anakin or Obi-Wan could’ve been argued to be the main protagonists, with Ahsoka being a side-character, but I don’t think Season 7 leaves much doubt. You wind up getting a lot of Obi-Wan content in Maul’s story, and you get a lot of Anakin’s development in Ahsoka-centric episodes, so that makes things a bit more convenient.

Unfortunately Maul isn’t even introduced until Season 4 so this doesn’t help give a great deal of structure to those first few seasons. Perhaps a focus on the clones early on would help. Domino Squad, Rex, and the Order 66 chip conspiracy all play a significant part in the finale, so it’s necessary to include all of that as some sort of show-long side plot. ~~Personally I like to watch Clone Cadets, Rookies and ARC Troopers back to back, since I forget which Clone is which otherwise…~~