Counter it as if it were a 4-1-2n-1-2 (narrow diamond). Just recognize that he more than likely has either red arrows on the DR or blue arrows on the DML, so plan accordingly. 4-5-1 v-style might be best or if his MC are weaker than the rest of his squad, try 4-1-2n-2n-1 (the hexagon) with focus through the middle.