stun diminishing returns

So here we are again.. stuns/cc seem to be not sharing diminishing returns across classes. This is in something like dh/monk comps where they proceed to chain stun you to death without being able to do anything.

I'm pretty sure there's diminishing returns on individual class stuns but can this be extended to stuns from different classes. The result would be that if consecutive stuns are used by multiple classes, they will start getting shorter and player becoming immune after 3.