Thrawn offhandedly mentions that C’Baoth calling himself “Joruus” instead of Jorus is a weird stutter/mispronunciation that comes from his dementia. It’s worth noting that “Luuke” is not a character. He doesn’t speak or have any thoughts of his own, nor does he name himself; he’s a meat puppet C’Baoth uses to fight Luke and Mara at the end of the third novel. And in Hand of Thrawn novels that Zahn also wrote in the 90s, there were major clone characters who didn’t use this naming scheme.
Basically, the naming thing is entirely a C’Baoth character trait and fans sort of took it out of context.
