I don't see why that's such a problem when Dunn, who has LF experiance, would be playing LF in the shortest ballpark. Yes he's a butcher, but it's not like they need Willie Mays. The Red Sox lived off Jason Bay and Manny Ramirez in LF for an entire season. I think Dunn will do just fine.
Adam Dunn makes Manny and Bay look like Willie Mays, for one thing.
Beyond that, though, it's not that Dunn couldn't
work. But it's a square peg in a round hole kind of situation. He doesn't directly address the team's biggest needs. He's not a catcher, he's not a third baseman, he's not a relief pitcher.
He doesn't fit the bill as a replacement righty bat if the Sox fail to retain Beltre and Martinez.
As a LF, he would actively stand in the way of revisiting this year's notion that, while Ellsbury is a middle-of-the-pack CF, he could be a premier defensive LF. As a 1B, he's forcing the team to move a gold glove player out of that position. As a DH, he's not good enough against righties to match Ortiz's production, and not good enough against lefties to be an unconventional platoon partner.
If you sign him, you're gaining in some areas, but sacrificing considerably in others – and it all but necessitates rethinking other parts of your roster to make it work. That's not impossible, but it seems like it would require too many moving parts to be a logical Plan A.