influenze is correct, the "Butterfly" is:
--------ST---------
AML----------AMR
-----MC--MC-----
DML----------DMR
----DC-DC-DC----
so the Butterfly and WM are the same on the attacking side, but different on defense.
The "Table of Counter Formations" recommends that the Butterfly be attacked with the 4-2-2-2 Hexagon.
Maybe that's an effective counter for the WM also?