I have a theory about Scar's line "Decades of denial". I like to think he might be referring to past royal siblings he learned about, where the youngest sibling was never given the crown. So he was claiming he did this for all younger members of his royal line before him. In a sort of deluded, egotistical way.. I know Lion Guard exists now, but my theory predated that. And its not to say Scar wouldn't believe other cubs made to do the Lion Guard wouldn't secretly long to be a king like him.
Sounds like an interesting theory!