I feel the idea that Romulans in TOS were "honorable" is fan extrapolation. The Commander in BOT seemed to have qualms about the current state of the Empire, but he still followed his orders and conducted a sneak attack. The Commander in "The Enterprise Incident" didn't seem all that honorable with her attempt to seduce and turn Spock. ( Not that Kirk and Spock were any better
) So I just don't get the Romulans are honorable thing.
The Klingons in TOS are probably more complex than we give them credit for. Kang especially seems more than the scheming backstabber we associate with Klingons. One might say almost honorable. Kruge actually is closer to the scheming backstabber (literally!) than the three main TOS Klingons.