Arsene Wenger uses several tactics but particularly 1 with which he starts a game.
Basic: A GK to CB's, 2 WB's, 2 CM's, 2 Wingers, an advanced play-maker and a a forward.
GK: Normal good GK.
WB's: The left is generally pacey and pushes up higher and has good finishing. Also likes to run with ball. The right WB likes to cross more (cross from byline) and does tight marking. Both WB's should have a supporting mentality.
CB's: A limited defender and a central defender. Both defender should mark tighter, the limited defender will tackle harder whereas the central defender will pass shorter.
CM's: A deep-lying Playmaker (DLP) and a Ball Winning Midfielder (BWM). The DLP should pass shorter, few risky passes, mark tighter and close down more and only defend. The BWM should mark should dribble more and pass shorter and provide support.
Wingers: An inside forward (If you are using Walcott then on the right) who should only attack, get more forward and shoot more often. A left winger who can roam from position and provide support.
Advanced playmaker (AP): You can use an enganche but he may not be much use against top teams. Makes sure he uses short passes, gets further forward and takes more risky passes. Set his mentality to attack.
Forward: A target man if Giroud and make him to hold position and dribble less. Set mentality to attack.
Team instruction: Mentality- Control, Fluidity- Fluid.
Other Instruction- be more expressive, play wider, tight marking, offside trap, roam from position, shorter passes, hassle opponents, roam from position, much higher defensive line. (select only 4 if you are telling them to be more expressive)
NOTE:
1) Arsene Wenger plays much more defensive against tough opponents.
2) Arsene Wenger uses Wilshere as a right winger.
3) Wingers should have high dribbling ability along with crossing.
4) Use 3 players with creativity of at least 15. The BWM and AP should be 2 of those 3.
5) Right WB should have good crossing ability. (In game Sagna doesn't but Jenkinson does)
6) Arsene Wenger doesn't use tiki-taka style were the tempo is much lower but rather one-touch play.