I find Noga's book difficult to use...in general. It relies upon case studies. You really can't just look up symptoms and figure out what's going on.
Stoskoppf is a bit better...but still difficult to use.
Untergasser is actually pretty decent...and it shows you how to do proper necropsies/scrapes/etc. A bit outdated, though.
I honestly agree that Fish Health Management by Tetra Press is one of the more useful books you can have. Along with their Aquariology series. A lot of people bash them as being "low level", but in reality, they are more useful for the home aquarist than anything else I have encountered.