I take this to mean actual equalization in the real world, not simply a
theoretical abstraction (please correct me if I am wrong). If so, then
the statement is incorrect. Actual equalization of profit rates is not a
logical prerequisite of the logically prior determination of the total
amount of surplus-value and the general rate of profit. The only
prerequisite (or implication) is that, if some industries have a higher
than average rate of profit, then this must be offset by other industries
iwth less than average rate of profit. The total amount of surplus-value
remains unaltered in this non-equal distribution of surplus-value. This
was Mattick's critique of Baran and Sweezy's Monopoly Capital.
Looking forward to further discussion.
Comradely,
Fred