Keith Law is in the prospect business and the Rangers are one of his favs. So he needs to be discounted some, imo. He said we should trade Sale straight up for Profar....the dude likes prospects (and yes part of it is he sees Sale as an injury risk, but still that's absurdly low on Sale). And I think Peavy's more valuable in the trade market anyway (BTW, your Starks article didn't say otherwise).
And honestly, for a team that was said to be "Great" 2 years ago (a lot of hyperbole to be sure), and replete with talent on the farm, the Rangers are kind of hurting. They haven't gotten much out of their farm.