I did some research a couple of days ago as I have said for a while now that the main reason for Chelsea's success has been their ability to play the same XI every week and the fact all of their players are in their prime.
I believe Zouma may be U25 but I think I am right in saying that before yesterday, Chelsea had not started a single player under 25 all season.
Yes they are a good side but i strongly believe both Utd and City have higher "ceilings" with the likes of Pogba, Bailly, Rashford, Shaw, Martial, Sane, Sterling and Jesus all bound to improve significantly (I dont include Stones he is shite now and will be shite in 3, 5 & 10 yrs time!)