Is there an actual conflict of interest when a defendant is at odds with co-defendants who were more culpable?

"An actual conflict exists when a defendant is placed 'at odds with co-defendants who were in fact more culpable.' " Lockhart, 250 F.3d at 1231 (quoting United States v. Allen, 831 F.2d 1487, 1496 (9th Cir.1987). "[W]here a court justifiably finds an actual conflict of interest, there can be no doubt that it may decline a proffer of waiver, and insist that defendants be separately represented." Wheat, 486 U.S. at 162.