Board Thread:Theories and Speculation/@comment-31099706-20170327120301/@comment-25122992-20170421163739

Well, I always thought Itachi had talked about the backup to their enemy's side (since they were in Konoha where more leaf ninja could always come to face them in the case the fight would drag on), but anyway, Itachi didn't specify what kind of backup they can receive, and it's quite obvious that all the Akatsuki members wouldn't be sent alltogether.