It seems to me probable that Brennan would have known of Steele from his CIA days. I wonder if Brennan - knowing of old Manafort’s linkages to the Podesta group - colluded with Steele to approach the Russians, and then in turn have the law firm hire Steele.
Brennan should be asked if he knew of Steele prior to the dossier, and had any conversations with him regarding Trump.
Just seems kinda of odd they hire Steele, a Russia House man, right out of the gate to investigate. That was his expertise. Unfortunately, for them, it is blowing up now in their faces.