Man City have been building their squad and spending money year after year just so they could compete well in both leagues. You can't really say which team has a better form since City also defeated Arsenal in their last match. We'll see how things go from here but my point remains that 5 points ahead with 11 games left doesn't make the Gunners too far ahead. They could also choke. Remember that they are also competing in the Europa League and that could affect their squad too.
However the competition is still ongoing and the standings are still very likely to change.
No one can say for sure who will win the title this season between Manchester City or Arsenal. The two teams will struggle to grab for 33 points in the next 11 matches, so I still think Manchester City has the chance to surpass Arsenal even though Arsenal are currently 5 points ahead. Now every match is a final for these two team, and whoever manages to get 3 points in each match then they will have a chance to win the title.