Division of Labor and Dialectical Materialism

Contradiction is a special case of Differentiation, e. g. red and blue are different, but they are not in conflict with each other.  However, in any Dialectical system, all Differentiation is Contradiction.  Now, Division of Labor entails Differentiation, but not necessarily Contradiction.  Thus, insofar as Marx-Engels adhere to Dialectical Materialism, they cannot adequately represent Division of Labor.