This season is very hard to predict because I also have the same thought has yours but things are changing to different direction, I consider top 4 teams should be Arsenal, Liverpool, Manchester city, and Aston Villa, and now Arsenal have started shaking when we are still in the middle of the season and from the looks of things I don't think Arsenal will ever make it to the top again because Liverpool are leading them with 5 points and Aston villa with 2 points, Manchester City that have the same points still have an outstanding match to play which I believe they will win the match. Arsenal are just ahead of Tottenham Hotspur with just one point which I believe Tottenham Hotspur recovery will make it easier to overtake them because Arsenal performance are dropping down.
You are right, Arsenal experienced the same thing as Tottenham last month while at the top of the standings but suddenly the performance decreased well Arsenal are in this phase and we don't know whether they can get out of this bad situation, on the one hand Tottenham and Manchester City has successfully stabilized their performance then slowly take place in the standings now we are waiting for Arsenal's turn. Previously Liverpool also almost experienced the same thing but fortunately they can overcome it quickly and returned to consistent with every game, for now the only club that can disturb Liverpool is Manchester City they look better prepared to start the race after the half of the season.