Quote Originally Posted by rappa View Post
All dots you put are doing damage the same time. But not all of them crits and trigger the river of blood trait.

In our rotation, we put GCD weaponskill > Empy > weaponskill because Empyreal arrow hasn't GCD per se. Sometimes you can't use bloodletter because you have to use Iron Jaws after Empyreal arrow and you see the bloodletter proc refreshed.
And just to add on, each enemy has their own global dot tick as well, which is also why you'd see multiple refreshes in one GCD window rather than one every 3 seconds.