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.
Manchester City have been investing in their team with the main objective of winning the Champions league trophy for the first time. For four years straight Manchester City have dominated the premier league but it seems Arsenal are up to the task and ready to compete till the end for the trophy. Arsenal are looking so confident this season and will be a tough opponent for Manchester City.