Manchester City's top form and performance in the league has now become a trade mark and tradition. They have the quality to execute the job and be in the top four and I think that just explains how they have managed to dominate the league for 4 out of 5 seasons. I also don't think the busy schedules will cause a break down in performance for Manchester city after the break. 5 points gap is not so much and I won't write City off at this point even with the gap from Arsenal.
Consistent results over several seasons with City are directly related to very large funding, this will be the norm until someone appears who will invest even more money in another club, Newcastle can be an example. You can also see which of the teams in the Premier League spent the most money in the offseason, it's not hard to guess that it was Arsenal. Big traditions can be replaced by big money, sport has become different...