It is not "impossible" for Liverpool to win the title, there is a 15 point difference and it's not something that can't be covered but lets be honest and just realize that it won't happen. We have seen Liverpool trail City with just 1-2 points and still lose because City refused to lose points, hence they kept winning and Liverpool ended up with points that would have been champions in most years, became second in those years because of Cities record breaking point championships.
All in all I think City will get it again, even though Arsenal is at the top, I still would bet on City to get it because they are a much more consistent team when it comes to winning games in premier league.
Liverpool winning the Premier League can only be possible if they have a rapid turn around with how they play from defense to attack.
Thry have to do more than Arsenal and Manchester City together, if they can achieve that then they can find way or themselves into the top four slots. As it stands, both Manchester City and Arsenal are the biggest challenge they'll face they may likely not end up with the three points.
I feel like it's time for Arsenal to get the premier league, they may lack depth and no much quality players to fight, but more consistency than they did during the first half round will make sense.