Equipping the heroic and non-heroic version of the same trinket at once

My question

I'd like to know if the heroic and non-heroic version of the same trinket share the same internal cooldown for its procs? Does this behavior differ between trinkets or is it the same for all?

Context

I own the heroic and non-heroic version of the Iron Protector Talisman wich has a very strong proc (chance on hit to gain ~3k dodge-rating; i'm a druid tank).

If both trinkets share one internal cooldown, it would be better to just put on the heroic one and use another second trinket.

If both procs are independent, putting on both items should result in twice as much procs compared to a single one. Since i don't have much alternatives at the moment, this would be my setup of choice.

My research so far

I was able to find some information on wowhead about the internal cooldown that seems to be ~45 seconds.

I couldn't find information about shared or non-shared cooldowns.