They’ve always felt that saving the Book was the best way. Sullivan had to convince them to do it this way, to protect us instead and let the Book burn in our place.
Sullivan was the one who had that faith in us. The one who believed the Magiq that would save the world and complete the spell would be ours, that we’d find a way.
His intent is, yes, to have us use the 94 Mounties’ BoB to complete our mission.