What matters if all of Arsenal players that left for the FIFA World Cup comes back correct and sharp without injuries then what matters most is consistency till the end of the season.
Initially, even if Arsenal was performing poorly this season, I'd still bank on Manchester City not to win the league because for personal reasons,I don't want the media saying Pep Guardiola has turned the Premier League to farmers league winning three times straight up.
If Gunner's can continue to win every little team and some of the big boys like they did, then, it'll be a short story to be told in a few months ahead.
Don't be too optimistic, Premier League still have next 19 match and the point difference between top 4 clubs are really close, with just 3-4 match Arsenal can fall into 4th position if they're keep losing. I'm not a Manchester City fan, but if you look on their players and Pep Guardiola that has various strategy, it's high likely Manchester City will win this season. The most important about Arsenal is they haven't fought a good team until now, when Arsenal vs Manchester City happen, we will know which club will win in this season.