I'll agree with you on Eric Hurley being a better prospect than Edinson Volquez, but not John Danks or Thomas Diamond.
Danks has a solid strikeout rate as a 21-year-old who has already spent time in AAA (9.90K/9), but his 1.41 WHIP and 22 HR allowed in a 140.0 inning split between AA and AAA dont' project very well in my mind. I think if Texas inserted Danks into their rotation now, he would get rocked even harder than Volquez. He still needs more seasoning in AAA.
Walking 5.44 batters per nine innings in 127.3 AA innings, Diamond, 23, is probably heading to the bullpen. His strikeout rate 10.11K/9 still shines, but a guy his age should have done more in AA.
All in all, the Rangers' DVD trio didn't live up to its hype this season. Send them back to netflix and try something new unless you are in a league with a very deep minor league system. I'd go after guys like Franklin Morales, Johnny Cueto, and Clay Buckholtz, along with Hurley over Danks, Volquez, and Diamond.
Mike Pelfrey > Matt Garza