that's because the guy rips them off by posing as them. it's just some kid recording covers in his room, someone told him it sounded like fleet foxes so he called it "fleet foxes sing". there's a small disclaimer on his tumblr, but he doesn't really make an effort to clarify. he's just looking for attention. look up "fleet foxes sing".
wow, what a disappointment. I have to say, props to him for fooling me into thinking it was one of my favorite, most listened to bands.