The solution would be not being able to proc a damage procsets within the cooldown of another damage proc set. That way several proc sets cant alone take someone down.
For example: Icy conjuror has a 10 sec cooldown. When icy procs no damage proc set can proc until the cooldown of icy is over
This would prevent healthproctanks or builds with 3 offensive damage procsets builds to rely on procdmg alone as their offensive toolkit
That way you can have 1 decent strong procset but procsets cant completely carry the majority of your damage