By 1970's Gooner
Arsene's teams in the last 10 years are unbalanced. Xhaka is not a holding midfielder neither is Ramsey. When the ball is lost in midfield there is no real barrier to stop the on coming attack. Ramsey is already too forward and Xhaka more often than not is unable to provide the defensive shield needed.
In the past there was a Gilberto an Edu or a Vieira. Now there is nothing of the sort. Look at Matic. He wins the ball and plays it simple to a team mate. This releases Pogba to be more forward thinking. Xhaka releases Ramsey but he is no Matic...
That's why Man Utd have every chance of winning the League but Wenger's Arsenal do not.