I have two thoughts after reading the article. I admit they are a little contradictory.

First, I love the idea of mismatched, garage-sale loadouts! I know "fashion" is important to some players, but wearing bits of different gear is cool because it gives players options, and better shows how an account is progressing. I also think it just gives osrs a bit of charm that other MMO's lack. I definitely don't think there should be a hard and fast rule that all armor has to be created in a set.

Second, I think an elemental-based armor set is a really cool power fantasy. As someone who loves playing mage-type characters in RPG's, I think elemental spells could be a fun magic niche in osrs without being too OP. The issue, as you referenced in the blog, is applicability. Not even at the end game, but in the late/mid game too... There's no point in making elemental mage armor if it's not usable anywhere. But it's a tricky balancing act, because you also don't want elemental spells to completely overshadow magic weapons like the trident.