After a good night's sleep, I still hate the deal. I believe individual relievers are overvalued in MLB. It's why I also hated signing Chapman to a huge deal. There is no denying that bullpens are extremely valuable. The Royals of whatever year it was demonstrated this. Individuals that make up bullpens are not that valuable. There is no huge shortage of adequate relievers. Relievers are almost all flawed pitchers who excelled once they were allowed to let loose over one or two innings and focus on just two pitches. Obviously, not every failed starter becomes a good reliever. Kahnle has already proven himself so he is certainly an asset, but I just can't get behind trading a valued commodity for a relief pitcher and two rentals.
The notion that Rutherford would never play outfield for the Yankees is irrelevant. He was a commodity that could have been packaged with other commodities to acquire something the Yankees actually needed.
By the way, Frasier is barely better than Headley, if at all.
Since 2012
Frazier: wOBA = .337, wRC+ = 111 WAR = 18.4
Headley: wOBA = .328, wRC+ = 109, WAR = 20.3