Does anyone know if tails on QX56 and Armada are the same Dimensions?

Wondering if taillight guards from Armada will work on QX, etc...

Similar but different. For example, the taillights are different. You'd have to look at the parts on a piece by piece basis. EX. taillight guards: How do they attach? Is the screw points at the same places or are they stuck on? Etc.

Do you know if the lights are interchangable? I would like to put the Q lights on my Armada.

No they aren't. Backup lights are not integrated into one but are on the other.