#2 A fighting spirit
The best part of the Invincibles or the Arsenal of the early Wenger-years was that they never gave up on a fight. Even if they went 2-0 down, they had the confidence and the toughness to ensure they could bring it back to 2-2.
This generation of Arsenal don't lack leaders but lack of the kind of personalities who can do something about the team having an off day. We've seen the likes of Francis Coquelin, Jack Wilshere and Alexis Sanchez rise up to the occasion and doing something about the team not performing.
A sense of being part of a whole and sticking together will take this team to a whole other level. Technical players and impact players are in abundance in this Arsenal side but if only the team had the 'killer instinct' most title-winning sides have, they'd easily stand a chance to challenge for the title.
The players are often seen slumping or losing interest once they go down or bullied a little. Bringing the fight to the team will definitely do this team a world of good.