Swanson has an WOBA of 465 and an xWOBA of 451. Definately not sustainable but his numbers aren't a fluke. He's hitting the piss out of the ball.
Semantics aside, with a HR/FB normalized to 10%-15% and all else remaining exactly as it is now, his current slash line would go from .324/.419/.765 to around .265/.360/.470. Folks are underestimating just how much a few early HRs can inflate a batting line.
An .830 OPS from Swanson is quite different than his current OPS of nearly 1.200, but still a very valuable SS.