"Red Clay" is tagged as "Post-Bop, Soul Jazz and Jazz-Funk" on RYM but it should probably count as fusion ("jazz funk" is basically synonymous) and I rated it 4 stars so go ahead and add it to my list. Hubbard also put out some amazing live albums with Hancock and Turrentine (Herbie really should have gotten top billing since "Hornets" and his keys dominate) but Ryan's not doing live albums.
"Fusion is an expansive genre and there's an enormous difference between Bitches Brew and Head Hunters."
Yeah totally. Though a few folks made reasonable attempts to ape Miles's fusion style (Henderson's "Multiple" and Young's "Lawrence of Newark" might be the best examples) he's sorta in his own category. It's simply grittier and funkier than most groups were capable of being. And though Herbie's stuff is much closer to standard fusion, he's clearly operating at a much higher level than most other fusion artists.