I've never got on with the Fleet Foxes - it seems too nice.
Check out Mountain Man instead, who sing beautifully and seem to be what Fleet Foxes only imagine themselves to be.
I think Fleet Foxes are exactly what they are - their sound sounds almost mediaeval to me in parts, but clearly they aren't from the C14th. I am sure Mountain Man are good too and I will check them out. But why does this always have to be an authenticity competition?
Remember Creedance Clearwater Water Revival? Awesome band. Were they really 'born on the bayou'? Were they fuck?
Midlake's first album was based on an imaginary late C19th complete with a whole cast of oddball characters but with music in the style of the the late 60s/early 70s LA sound. Not remotely 'authentic'. But brilliant.