Matt Shaw was horrific in Japan and IMO a bundle of nerves. But he's got a 113 wRC+ and nearly even walks and strikeouts since getting back stateside. On top of that he's got a .341 xwOBA to a .322 wOBA domestically, so I'm not sure the luck argument holds either.
There are some ugly swings, he's getting beat in-zone more than I'd like, but I don't see any reason he should be at Iowa.