#4 More direct play
One of Arsenal's most vocal criticisms is that they don't have a plan B. Once the free-flowing passing hits a brick wall, the players don't know how to adopt a new approach to win the game.
If Arsenal are to ensure they become a tactically complete side, they must add another style of play to their arsenal (excuse the pun). A more direct approach in games more suited would allow Wenger's men to overcome all obstacles.
Direct long balls allow a team to bypass the midfield battle completely, allowing attackers to get in behind defensive midfielders and face defenders 1v1 quickly. Direct balls quicken transitions and force defending teams to engage in aerial duels more often.
With Olivier Giroud playing up front alongside Danny Welbeck, Arsenal could have two 6-footers occupying centre-backs thus allowing the wingers to pick up the second balls.