These are all of the players that are better than Hiura in the International League:
What Hiura is doing in AAA is nothing and means absolutely nothing. If he were in the teens with his K% I would start to think he has turned things around but he is not doing that.
At best Hiura is probably the same as Perkins and Topa but both Perkins and Topa have an advantage over Hiura they can actually field a position Hiura can not. When you have a bench player and that is what Hiura is having that bench player only being a DH is going to hold that player back. Hiura would have to be at the level of a Manny Ramirez, David Ortiz or Prince Fielder to be valuable. He is not anywhere close to that even replacing Winker with Hiura doesn't really move the needle all that much. If anything it probably makes the team worse.