If he uses this formation

----------st-----------
-aml-----amc-----amr-
----mc---mc---mc----
----------------------
-dl-------dc-------dr-

you should use this to conter him
-----------st-----------
----------amc---------
-ml---mc------mc---mr-
----------dmc----------
-dl--------dc--------dr-

PS. please show me the result after using this so I can suggest this to other people next time