Only Dragon armor?
What in the name of god is the point of forcing you to take TWO perks to make inferior dragon armor.
My best guess is that it allows you to improve your armor to legendary quality
So in the end it would be a choice between being able to craft dragon armor which seems easier to make and being able to improve Daedric for additional 5% ( from the screenshots I assume that Dragon armor has base armour of 96 and Daedric of 100)
Or you could take 1 less perk and being able to improve daedric to 120 armor (which is equal to highest quality Dragon armor) but you would be able to have a set of 120+ armor a lot later in game
So it's 1 perk for 5 armor in mathcraft (for highest armor piece, so let's say it's 10 armor for 1 perk, seems like a good perk to me)