This is a pretty simple question, If a team would settle for only one, who would you trade for the real power hitter that we need?
I think the we should obviously keep Tillman, but he's also more valuable than Arrieta. But... Arrieta is just plain cool.
Tillman: 22 Years old, still devolping his pitches, better stuff, probably a brighter future as a top of the rotation starter. But more likely to net a deal with someone for the big bat.
Arrieta: 24 years old, A little less command than Tillman (at times), easier to keep, harder to get the big bat without giving up more.