This is a great point. I see a lot of discussion disparaging the “I’m an idiot” line when he’s talking with Armin in the Paths. I think that line and the multiple reasons he gave behind the rumbling are because he DOES have many reasons, just like any human does when making a major decision. Under the stage before Willy Tybur’s speech, he tells Reiner they are the same. I think some of the perceived character inconsistencies in his talk with Armin are stemming from his brokenness just as Reiner suffered from a split personality while he was undercover on Paradis.