The guy having only 3 players on his side of the field has plenty of weaknesses:
----DC--DC--DC---
--------------------
------MC---MC------
AMR----AMC----AML
------ST---ST------
16,4 stars me, 15,2 stars he. We both were present at the match and he had 4% possession bonus playing home.
The first half I was playing defensive with counters, passes center and long. I call this formation Christmass Tree:
--------ST-------
-------AMC-------
-----MC---MC-----
-DML---DMC---DMR-
----DC--DC--DC----
It was complete success. This formation is definitly good counter and can be recommended. He had no comment about attacking in the first half! Although I was defensive, the comments were only about me attacking. I had possession 60%, more shots on goal, more corners, etc. And I won first half 0:1.
Second half he changed formation to "normal" 3n-4-1-2 and the situation changed dramatically. I had 2 yellow cards, he scored once and failed penalty. So, Christmass Tree definitly not recommended as counter for 3n-4-1-2.
I changed to my usual 4-5-1 V attacking and won 1:2 in the end. Possession and everything else approximatly 50/50.