Don’t trust the tooltips. Trust only the numbers on the main screen. Record and replay in slow motion if you have to so that you can clearly see what’s going on. I previously did some research on Cadence + DW Melee WPS interaction. In a nutshell:
- Cadence 3rd Strike can combine with WPS. The Cadence hit replaces one of the WPS hits. Multiple replacements for multiple targets are possible with Fighting Form and if the WPS is also multi-target. I don’t recall what happens when a target is inside the AoE of the WPS but outside the AoE of Cadence (e.g. Whirling Death). I also don’t know whether simultaneous devotion procs are possible. I do vaguely recall that if the number of targets in the AoE exceeds the target limit, then the closest ones get hit.
- An attack with both hands results in a free Cadence charge. This can happen with both WPS attacks and a normal DW attack that hits with both hands.
The above applies when you are holding down your mouse button, which is what actually happens in real combat. There is different behaviour for single isolated clicks.
My research was peer-reviewed by thejabrixone in October 2018: