Thanks for the responses.

The reason I figured his consigliere was ineffective is for several reasons: this includes not stressing the importance of attending Dellacroce's funeral, not telling (or convincing) Castellano how deeply despised he was by his rank and file and why, and letting Castellano act passively towards the Gotti crew once Ruggiero was arrested. I've always been under the impression that the consigliere was in the boss's corner and his well-being was his top priority. The fact that he counseled three different dons would lead one to believe that he was intelligent enough and had the gift of persuasion.

But like you alluded to, Pizza Boy, Castellano was a grown man with frightful power who apparently lived in his own small world and no one could force him to do anything that he didn't want to do no matter what.