And it looks like you're missing #3 and #4 for the Rihanssu books. My Enemy, My Ally is #1, The Romulan Way is #2, and The Empty Chair is #5, you're missing Swordhunt (#3) and Honor Blade (#4).
Although those are really a single book, Swordhunt, that was hastily split into two volumes (not even renumbering the chapters) when the real second half, The Empty Chair, was delayed but they still had to fill the contracted two slots in the schedule. And in between, Swordhunt (along with MEMA & TRW) was rewritten in The Bloodwing Voyages to take place post-TMP when the original 2-volume release was set in the 5-year mission.
Not to mention that the Rihannsu books are part of a continuity that also incorporates two non-Rihannsu books, so the real sequence is The Wounded Sky, My Enemy, My Ally, The Romulan Way, Spock's World, and Swordhunt/The Empty Chair.
I like Drake.