Your conclusion, not mine. How does saying that it "is not acceptable English" help the poster gain a better understanding of the workings of the grammar? I would never offer such a conclusion, but you have offered it for me. Please do not speak for me. (It's becoming oh so terribly tiresome.)
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The problem: why can't 'of which on whose behalf' be shortened to 'of whose behalf' given that the syntax allows such an array (prep+possN+noun).