At the beginning of the season no one saw Liverpool coming, they played badly and at a time was battling to move to the big six, it was all Manchester city and Arsenal.
Now Liverpool sit 5 points clear of Arsenal and Manchester city with Aston villa their closest rivals.
I think in terms of consistency Liverpool are better than Arsenal and has a better chance of maintaining the top spot and would be Manchester city main adversary to them defending their premier league title.
Arsenal are very unfortunate. From 1st place they have to go down to 4th place and have the opportunity to go down to 5th place. Liverpool from the first PL match this season was immediately challenged by Chelsea, even though the result was 1-1 consistently, they could slowly be at the top of the standings.
Arsenal's consistency is in doubt from season to season and Arsenal is in doubt from competing for the title this time.
Aston Villa's consistency has also not been tested, maybe this season they will be serious competitors against Liverpool and Manchester City in the competition for the Premier League title after they last won this trophy in the 1980/1981 season. Or Aston Villa this season will be runners up after the last time they were in the 1992/1993 season.