Also, nice job comparing probably one of the most complex bosses in the game to one of the simplest ones. If you look at Immerseus, it's literally 3 mechanics (tank swap, swirl, kill/heal adds).
More mechanics is almost always a more interesting and fun fight for me. Siegecrafter, Paragons, Garrosh, H Dark Animus, H Durumu, H Spirit Kings, and Ambershaper are some of my favorite fights in the game, and yes I have played since Vanilla (didn't raid until BC unfortunately).
Edit: The post I quoted was the entire dungeon journal for Paragons. I snipped it.