I’m pretty much in the exact same spot so I’d like to know as well, but I’m pretty sure I have an idea of what I’m doing wrong (so this may or may not apply.) I tend to see 5k+ wars getting off a couple more fell cleaves during a fight so for me I think it comes down to not refreshing storms eye at just the right time. More reapplying of the buff translates to less beast gauge which also translates to less fell cleaves. People who know more than I do can point out other stuff, but I would expect this to be a common theme among wars trying to absolutely optimize their dps. Hope that’s helpful!