If im not wrong its Guehi and Colwill he'll be competing for as Englands left sided centre back.
While Stones was joined in the euro 2016 squad by Cahill and Smalling which shows the difference in quality.
The similarities lie in them both being able to pass the ball, bring it forward and are showing solid defensive ability far beyond their years.
So far, Branthwaite is physically superior and we'll need to see him over a full season before we compare their passing and defensive abilities. But im not sure how different they are in terms of overall quality and potential?
One thing for sure is that if we had a 21 year old Stones next to Branthwaite Id expect both to be in the England team together -- Branthwaite needs a chance.