I've touched on this on twitter, but not here, I actually have no problem with the Royals making this move. Well that's not quite true, I do have an issue with who the 6th starter will be but overall I think it's an acceptable compromise since its goal is to keep Danny Duffy on the roster.
A 6 man rotation, for however long it lasts (I doubt it lasts remainder of the year), will do much in reducing Duffy's innings. He threw only 62.1 innings last year and I would hope they wouldn't want him making 30+ starts this year. He has 15 right now between Omaha and Kansas City.
The compromise unfortunately also involved Kyle Davies. I'm not really sure what else they need to see out of him, he's 27 years old and sporting a career low 52 ERA+. 2008 is becoming more and more of a distant memory, it's time to move on. Seeing him pitch every sixth day instead of every fifth is the only bright side to his return.