Juventus have won nine titles in a row and Bayern eight in a row. In Spain it's a bit better with 15 out of the last 16 titles won by Barca or Real. Whatever Pep says the facts speak for themselves. It is a stroll for Bayern, Juventus, Barca and Real (perhaps not this season) in domestic football. These clubs save their energy for the CL and they get winter breaks. Burn-out is only a problem in England and always has been. That's why English teams have won so few Champions Leagues. That said if we get a good price I would sell Sterling because he has been brilliant in the past but won't get any better in the future.
It is for sure no stroll for Bayern - especially not this season. The only easy match this season was against Schalke at MD1. The new players have not settled in because of late purchases and the lack of preparation. And injuries in midfield did not make it easier as there is seldom chance to just let the ball move.
And running for results after going down 0:1 every match does not make it easier.