cadence and Weapon Pool System

Does it just overwrite any proc on 3rd strike, or chances pool to be 33 cadence, 66 other stuff?
Basically do i have to reach 100% of total proc skills to never use default attack, or just 66%?

Cadence third hit overrides every WPS proc.

They can’t trigger at same time? Like get all bonus and properties stacked? Dang.