Supplemental reading for hypnobirthing

My friend recommended "The Birth Partner" for DH to read but I'm wondering if it's necessary if we're already doing the hypnobirthing classes.  I worry that what's in that book might conflict with what is taught in hypnobirthing.  I briefly flipped through it and it of course talks about pain and suffering in labor and how to help your partner but if the idea behind hypnobirthing is that fear brings the pain to light and that the key is to not have fear, then could this undermine things?  I don't want anyone really to keep asking me about pain.  He's already reading the hypnobirthing book as well as "What to expect when she's expanding.". It's a pretty funny yet informative pregnancy book for dads to be.  Plus we also have the mayo clinic book for more intellectual pregnancy info.