I think champs, guards, and LMs are in the same boat, with each having several skills. (Couple DPS ones for champs, threat stance & Challenge the Darkness for Guards, Eagle & Ents for LM) Couple other classes have a single skill, but not too much of a big deal at that point.
Of course, it's not actually true now that we always have literally all of our skills. IDOME, SotD, and Oath-Breakers Shame are all only available from their legendary traits. I think some of the other classes are even a little more extreme, in terms of having some skills that are only available with certain traits, but I dunno. My Captain is my only 85, so there's a lot about other classes that I don't know.