FC, read the tutorial
'Justdomes' guide of being successfull Manager

especially the part on tactics and marking. Note also, that per Nordeus, arrows are the equivalent of moving the player's position forward or backward on the pitch. So an MR with blue arrows ~= a DMR with no arrows, and MR with red arrows ~= an AMR.

Forget all that use x formation against y stuff. Build your formation and tactics to stop your opponent and exploit his weaknesses.

Second thing to remember is that most of these guys have one mentality: throw everything they have at attacking.

I've won my league every season I've competed, done pretty well at CL, and fair at Cup (I've never won cup, usually competing against teams 2-3 levels above me). I typically play defensive/counterattack and usually lead league in goals. I very rarely play more than 1 striker. I have never bought tokens. Just to give you an idea where I'm coming from on this.

Justdome's guide was invaluable to me in figuring out how to set up formations, and usually after i set my defence and my attack, leaves me 2 players to position according to my tactics, which gives me quite a bit of flexibility. Further, with that understanding you'll know how to adapt your formation during a match. My style may not be comfortable to you, but with the formational understanding as a foundation, you can adjust your tactics to suit your team and/or your own style.

Oh, yeah, always remember this is a computer game of probability. It's not futbol. It's not even really a simulation of futbol. It's a probability program dressed in futbol clothes.