If Chelsea succeed in winning the conference league they will be European champions and if Manchester United fail to win the Europa league then Chelsea will be said to have a better season than United. At the time both sides are struggling to win games and stay consistent however Chelsea are still better than United because of their standing in the league table and until United win the Europa League title Chelsea are better than them.
Chelsea has a good chance to win this season they win this league with hard work and good performance and Manchester United and Chelsea's records are not equal because manchester united is weak if they win this europa league it will be a good win for manchester united Chelsea is the better because Chelsea tend to improve after losing a match and Manchester United have been keeping their list of poor performances for a long time. Manchester United had some chances in which they could have improved themselves but they kept their poor performance bad. Chelsea's performance is better than Manchester United's because they are playing with good performance and hard work.
Really don't understand what you mean by Chelsea has a good chance of winning the league this season because from what I see they have been nothing but absolutely terrible and have continued to show that although they had some kind of good spell but that too was over with the twinkle of an eye and when it comes to Manchester united then it's totally a different case because they poor performance had been nothing but sorrow all through but looking at their current stats and state now I think united are in a better position.