One reason I believe is making many think one team will win over the other is mostly because they have seen that these teams may be doing well in their various domestic leagues and probably have fantastic squad but even with all of that, it will be best to wait till the season kicks off then we for sure are going to see who has better potential at the champions league trophy over the others, the champions league will start weeks ahead and so predictions now may just be based on assertions.
The assertions also serve as support for the favored team, or indeed, look at the performance in the preseason and the early matches of the newly started league. To play it out more, we can indeed assess the strength of each team once the competition has begun. A team with a fantastic squad is not necessarily going to play well in the Champions League. They could be unlucky to face a strong team.