For me no team asides of Manchester City and Real Madrid can have a chance right now to become the champion of the season of UCL, the 15% for Bayern can be accurate but also overstimate, because they havent played against any good team until now. And this Bayern is going from less to more, but lets see how they do against big teams, against a weak Man utd they strugled a lot.
I couldn't agree any less with you, Manchester city and Real Madrid not only perform so well in their group in the champions league but they aswell perform brilliantly in their various domestic league where they are at the top of the table showing how well informed they are in their strength, they both have some level of consistency aswell.
Bayern Munich isn't a team to underestimate because their domestic league where they play too isn't an easy one, they also have it very competitive there aswell yet they are doing well and back at the champions league they aren't performing any less although it seems as if they are yet to meet teams who are in better form as compared to those in their group but then they will most likely still have they form to face other tougher team after the group stage and probably get a good result.
On paper, Real Madrid, Manchester City and Bayern Munchen are indeed very superior, the three clubs who have recorded perfect points in their 4 group phase matches so far without defeats or draws. In terms of squad depth, these three teams are very good, they have almost equal rotation options so they are able to show stable performance in the top two competitions. This is the main factor in their success every season, when faced with player injuries or card accumulation they are not too bothered by these two things, even though sometimes the results do not match expectations.
I think all the clubs that are currently struggling in the group phase have the ambition to move to the next stages, and will try to match the positive results in their respective domestic leagues. But there are only 16 teams that can advance from the group phase to the last 16, Bayern, Madrid and City have already confirmed themselves to qualify first, followed by Real Sociedad and Inter Milan.