Anatomy: For my particular test, yeah probably. I did read HY: Anatomy though because I know some people have had more rigorous anatomy questions than me. Plus, I was weak on radiology scans and I felt they were helpful. I didn't really need it, but I felt better having studied more.
Embryo: Absolutely. My embryo questions were very basic, core embryo concepts. I still read HY Embryo early on though, because I'm an Embryo freak. But any normal person should probably just do FA.
Histology: Unless you've had major problems with the subject in the past, I don't think much/any additional study would be needed. Maybe bundle a bit with your Cellular/Molecular Biology studying.