I first played this game the day of the official release. I started an Arsenal save and set my tactics, team instructions etc. 3 hours in I was getting frustrated. I play the game on 2d because I find that the animation and the physics look dodgy on 3d and I can analyse the game better top-down. 10 matches into the season and I was not doing well. The games were too open and I was conceding often - a bit like Arsenal IRL really. I also read about some of the bugs (defenders poor on crosses, slow to respond to attackers running with ball, outrageous long shots conceded etc) and so decided to give the game a few patches and play again. Since taking it back up I have also read some of the wikis and other tips about setting out the team. Arsenal have pooor decisions, poor marking, poor positioning and poor leadership all round according to FM (and thi would appear to be the case IRL. So, I have had to change my management style, have a more rigid style, use man-marking, stick to position and stand-off more. This of course is anathema to what Arsenal do IRL. It is now 15 games into PL and Arsenal have 21 points and are in 10th. In the save I am top on 25 points after 10 games, having lost once to Man City at Etihad, and drawn at home to Newcastle.
I don't read anything into this other than I have adapted a tactic to the players at the disposal of the club. I bought Fellaini and Enrique in, and sold some dead-wood, but in the team comparison page the squad is still woefully inept at marking, positioning, decision-making and other mental attributes. I have noticed that these attributes are often the deciding factor when players are similar in terms of physical and technical attributes. Using too fluid a style or allowing too much attacking and creative freedom should lead to more opportunities created against the side, and so I have put restrictions on them. Also, other than Giroud, after 25 games I do not see an offensive player in FM Arsenal to equal the Manchester clubs, Chelsea, Tottenham, or many of the Europa clubs.
In short, I think this game is less forgiving when you try to do an AVB on the team, and make them conform to a style unbefitting of them. If you have slow defenders such as Mertesacker, don't push him over the halfway too much. If you have young, inexperienced full-backs don't tell them to be Dani Alves. If you have a midfield with poor stamina and work rate, have them close down only in sensitive areas of the pitch. If you have a tall, imposing striker play float crosses and play as a TM. If you have a wide player with poor crossing/passing/technique attributes (i.e Walcott), then try having him drill crosses rather than attempt to pick out his man. Play them all to their strengths and they will perform.