I never understood where this "Romulans are honorable" thing came from.
In all three of their TOS appearances, Romulans are scheming bastards, totally devoid of what one would call honor in a human society. First, they perform a cowardly sneak attack with an invisible ship - and are busy stabbing each other in the back during the mission! Then they hide in warships in the Neutral Zone where they ambush a mission of mercy and pound it with their weapons, oblivious to the hails of the victim. And then they are seen operating ships that look like Klingon ones, no doubt to some devious purpose, and again they backstab and scheme and bribe and betray.
Compared to these folks, every TOS Klingon was downright honorable. And even if Kras from "Friday's Child" or the goon from "Elaan of Troyius" were using sneaky tactics, they at least fought "honorably" once challenged. Kor showed typical warrior honor through and through, keeping his promises, respecting his enemies, showing mercy towards those who fumbled and grace in defeat. Koloth was nothing but polite and gracious, and readily withdrew when his subterfuge was exposed. Kang was the very model of the modern Klingon general, not a step behind Martok or Worf in this warrior honor thing.
Kruge would seem to logically follow this continuum of Klingon personalities: a strong leader with strong ideas on honor, even if constantly using guile and deception to defeat his enemies, and showing contempt only to those who couldn't hold their own against him.
In turn, very little from the books of Diane Duane sounds true when the continuum of Romulan behavior is considered. Duane seems to be describing a lost world, a bygone time whose disappearance the commander in "Balance of Terror" can only lament...
Timo Saloniemi