Could just do the same thing with Mythic/Arcanes and make the vanity-ifiable for an Arcane shard.

On another note though, gear drops in lower levels probably needs an increase because gear progression is really bad. Found myself going from using literally whatever was best and most cost effective in CS (there wasn't much) when leveling to the 'standard' legendary gear around level 57. Then got a proper, actually good set of gear at level 66. Gear progression is like > Garbage Gear>Garbage Gear> Average Gear> Best Gear.