Drakebreaker shield vs. Off-hand upgrade price

You need 5 Trophies of Strife to upgrade an off-hand for a caster, but 7 to upgrade a shield. My monk and shaman healers got the same slots upgraded, but monk still has 2 Trophies to work with next week.

I know it doesn’t matter much on the long run but… All casters can have their MH + OH upgraded for 14, except for shield users. This doesn’t feel fair to me, am I missing something? Is it possibe that this is an oversight and is worth reporting to Blizzard?

Edited to add: dual-wield dps classes also spend 14 on their two weapons, so it’s really only shield users who get the short end of the stick here (and fury warriors but I guess that’s the nature of the spec?).