Statistically they look the same, so this is really not an easy match for them. Both Chelsea and Manchester City need a win to maintain their position. But in terms of appearance, they can also be said to be the same when we look at their statistics in the English League this season.
However, Manchester City has another advantage, yes they will play as hosts and usually the team that plays as hosts is more favored to win the match. On the other hand, they also have to play a match in the Champions League first which will be very draining.
Even without looking at Manchester City's performance in the Champions League, there is no way they can win Chelsea when they meet because despite that Chelsea have been slacking for a while now, but they are stronger than Manchester City regardless that Manchester City won their past few games in the Premier League. Chelsea has a stronger attack than Manchester City and they have ball control unlike Manchester City that can easily lose possession to their opponent. This is an opportunity for Chelsea to retaliate the loss against Manchester City in the opening match of the season and i believe that Chelsea has all it takes to overpower Manchester City and win them now.