Am I missing the point of the cooldown? Because as far as I know, Rampage doesn't stack with itself, and the way cooldowns work with procs is that the cooldown only fires when the proc activates.
Since all the durations are longer than the cooldowns, I'm not actually seeing the point of the cooldown at all.
I'm not sure if Rampage should get tied with Frenzy, since some builds can have Frenzy on practically forever. It would effectively turn into a straight up speed buff for any build that consistently goes into Frenzy, while being comparatively useless to other builds.