1
Ya, really in the past 2-3 years. Usually 3B is in between the glove positions and bat positions in production and I'd guess that it rebounds in the next few years.
The difference between 2B and 3B is a bit overrated though. You want balance. If a bat-first type can be competent defensively at 3B you can stick him there, but I don't see the need to risk it since we haven't seen what Seager can offer yet.
A mid-high 700s OPS would make Seager one of the better offensive 3Bs in baseball, especially considering Safeco.