I imagined a scenario that went something like this:
Twins get: Greinke
My reasoning: This trade doesn't include any of the Twins' 3 biggest-name prospects (Gibson, Hicks, Sano), but some report Wimmers to not be far behind those 3 (John Sickels ranks him above Hicks and Sano), and Revere and Arcia are probably top-10 prospects too. The Royals get a starter who steps into Greinke's spot right away, another starter not far from the majors who may have a higher ceiling, a position player who's almost ready, and a high-upside lotto ticket from the low minors. Wimmers is a PTBNL because he signed less than a year ago.
I almost put Manship in Slowey's place but thought that made the package a bit too low on value. I would gladly replace Slowey in this deal with Blackburn plus cash to offset some of his bad contract, but that probably wouldn't fly.
Another point of comparison is the package the Twins got for Santana - a trade for Greinke should probably send somewhat more value to KC than the Mets sent for Santana, and I think this one does.