Yeah, all the numbers can give the impression of accuracy when the reverse is true.
For example, my $10 -to- $40 value range is far from precise! But it has been helpful in giving me the confidence to buy heavily at $11, with the simple idea of holding until I see something more in the middle. But if the price goes to the middle of that 10-to-40 range in the near term, I won't have any idea at all of what comes next.
I'll check out the Damodoran thing. Clearly price needs to enter the picture. If I just fool with that exact formula, though, and pretend that the business equity is equal to the book value, then I get something like: