That is, the Twins are going to need some left handedness.
Left handedness could be a tie breaker if they were tied. I think Wright is the better pitching prospect.
i don't think you swear off all left handed hitters obviously, but it feels like you have to have a certain type of power from that side. A Vargas is fine. I don't know how McKay grades for power but I've heard 20-25 as a possibility so that would put him as above average to plus. Does that reduce in Target Field? I think it's a legit concern.
Looking back, The Twins haven't had a huge sample of lefties with power either: Thome, Morneau for half a season pre-concussion, Kubel, Arcia and now Vargas switch hitting and if Kepler develops it. So I guess it could be the sample size but I know even some of those guys had a harder time hitting them out in the new ballpark.
I agree with your last comment about Wright though. I do think if it's pitching wise, I'd go Wright over McKay.