While I suppose qualitative arguments can be made regarding definitions for your term, "best case," and the ABA's terms, "effective, quality representation," I would contend that from a purely ethical and moral standpoint, neither the "best case," nor "effective quality representation," consist of blaming or smearing the victim.
Certainly, I understand that in the real world, many prosecutors and defense attorneys have less interest in justice being done than they do in chalking up a win, but at least in theory, a defense counsel's duty is to justice, and ensuring that the defendant's rights are respected in regard to the application of procedure.
Fair enough, but if I am ever accused of a crime you’ll forgive me if I don’t ask you to represent me.