There’s an episode of Enterprise, I don’t remember which, where Captain Archer is represented by a Klingon lawyer. They talk about stuff, since at this point human diplomacy with Klingons is almost non-existent. I remember the lawyer mentions that the warrior caste taking so much power is a somewhat recent trend, that Klingon society used to be more diverse.
This goes along with what you see in Star Trek VI, where Klingon society is crumbling due to internal tensions.