It looks pretty uninspiring, is how it looks.
Byproduct of the lack of legit pitching prospects, gutting the MLB salary, getting fleeced in the Polanco trade, and lack of any other offseason attempt to bolster the rotation.
My personal guess is SWR would be the first callup, but as jorganswest notes above, timing will most likely matter.
And more than one of these four will almost surely get MLB starts anyway, so who is first probably isn't all that important.