Manchester City managed to win two titles last season and I expect their performance to continue in this season as their coach is one of the best experienced people. I think Manchester City will do great this season under his leadership.
Manchester City didn't win two trophies last season, they won a treble (EPL, CL and Fa Cup), and despite that outstanding feat, they are still favorites to retain all the trophies they won last season, though it definitely won't be easy. Having said that, Pep is so important for City, he is a serial winner who doesn't give any room for complacency, even as City won a treble last season, he would continue to push his players to win it again this season, that is why he is the best manager in the world.
It will be quite difficult for Manchester City to repeat their last season victory again in the coming season. A particular club winning treble in one season is not something that can be done consecutively. No matter how good you are and how quality your squad depth is, you would still not be able to win three trophies in the same season because some good club must have emerged. For instance in the English Premier League, Chelsea will try to perform better than last season because they did not have European competition to play this season.
But then Manchester City is in all the competitions and they would definitely suffer injury or fatigue, which would make them drop in their pursuit of one trophy out of the three?