Board Thread:Manga/@comment-24930713-20150810080743/@comment-24407809-20150818205440

Manuel de la Fuente wrote:

Actually, that's not necessarily true. We know that Keith rejected Erwin's strategy when Erwin initially proposed it, but he could have been convinced later after the continuous casualties that his squadron was experiencing, while Erwin's squad wasn't losing any member.

When Erwin proposed the strategy, Levi was nowhere to be seen, and during the events of No Regrets he had recently joined the Survey Corps; that suggests that No Regrets could take place after that part of Bystander. Hmm... I guess that's possible. I always just assumed that he rejected it, and it was Erwin's success keeping his squad alive that made Shadis decide to resign and appoint Erwin commander, which is when Erwin began using the strategy himself.