Manchester City is really into easy group because they only will faced Leipzig, Red Star and Young Boys so we all know Manchester City squad quality is far above to these teams and certainly they will advances to the next stage with smoothly because possibly Manchester City will beat all of them and on the paper Leipzig is became an the second team who possibly will qualified but they have bad experience when they met Manchester City last season because on round of 16 Leipzig has been humiliated by Manchester City with huge scores 7-0 and i am sure they have ambition want to get revenge but i think it will be very hard because Manchester City currently as one of the strongest team in Europa and not much team who can able to beat them
Qualifying from the group phase to play in 16 rounds is enough for Leipzig, they don't need to struggle to beat Manchester City because City is indeed the strongest team at the moment and hard to beat, as long as they can beat the other two teams both home and away then they have enough points to be in second place and with Manchester City playing in Top 16.
Manchester City is lucky with this draw because, throughout the group phase, they can focus more on continuing to win many matches in the English Premier League, or at least they can rotate players well.
As defending champions Manchester City will fight to reach the final, but when the draw for round 16 will also be quite decisive in my opinion, if they get another easy draw it will really help them, and favorite teams like Manchester City often get this convenience.