Hyperbolic???
They originally wanted 139,000 square miles set aside just for buffalo. The only states in America larger than this are Alaska, California, Montana and Texas.
Noss was looking for half the area of the United States to be mostly off-limits to human beings. I'd love to know where your cutoff point is for calling something hyperbolic.
As for small wildlife corridor projects, I have no real objections to them providing they are, as you say, comprised of land that is already public or sold by willing (key word) sellers.