Well its what every good team does when you know vividly that the attacking line of the opposite team is way stronger than yours. What you do in a situation like this is always wait and pounce on a counter attack of which was very effective at their own end as they capitalize at every chance they get and scored thrice which was very good from them.
As good as Bayern Munich is poised right now, no one would believe they could have been beaten with three straight goals to none by a club like Feyenoord. Could this defeat be caused by the smoke from flares that got into the pitch and made visibility almost difficult for the players. Although that caused the game to be suspended for minutes before they resumed again, not long ago, Gimenez made the Feyenoord team proud with his goal. The three goals scored by the team was stunning because everyone least expected this outcome and was marveled by the end of the game. Both Kane and Jamal Musiala made great attempts to net the ball for the Bayern side but both great opportunities were thwarted by the goal keepers proactiveness to protect their goals.
Manchester City's performance has been kind of poor, but that doesn’t mean they are going to sack Guardiola. He has really achieved a lot for Manchester City, so just because his performance is bad this season doesn’t mean he will be sacked, so we shouldn’t even expect Guardiola to be sacked only if he wants to leave the club.
At the moment I do not even think it is a good idea to sack Guardiola from the Manchester City because if they make such decision and it wasn't examined carefully, it will end up becoming detrimental to the performance of the club in the short run. It will most likely destabilize the squad outputs and tactical formation of the club. I still see Guardiola as a good manager for Manchester City only that he's passing through tough moments with the team. A little more time and support Wil bring the team back to life the more.