Hear me out please. In my opinion this is long overdue. Especially with the addition to mythic sets added to the game. It would make the game better in the long run when it comes to sets and builds.
Only down side would be that Zos would have to get rid of one of the set bonuses to make it a 4pc.
Just some examples I can give on how it would make combo building better.
Combos:
1pc Mythic, x2 4pc set, 3pc set(example Willpower).
1pc Mythic, 4pc set, 2pc Monster, 2pc Weapon, 3pc set.
x3 4pc set.
x2 4pc set, 2pc Monster, 2pc weapon.
These are just a few examples. Let me know what you think.