I cant find anything vs this formation on the formation post.

His formation:
--------ST------ST---------
----------------------------
--------MC--MC--MC-------
------------DMC------------
--DL---DC--------DC---DL--


----------------------------
Formation I'm thinking about using:
--------ST--ST--ST---------
-----------AMC-------------
-------MC--MC--MC---------
-----------------------------
-------DC--DC--DC----------
And Orders.
Team Mentality: Defensive
Focus Passing: Through the middle
Pressing Style: Own half
Tackling style: Easy/Normal
Passing style: Mixed
Marking style: zoned
Force counter attacks = yes
Play offside trap = no

Would this work out? or is this 50/50?
Most of my team is better than his, like 70-80%

Your proposed formation is illegal as you have no players on both sides. I would play 3-3-2-2, swap the AMC and an ST for AML and AMR. He's more exposed down the wings anyway.