I think they can win the Champions League with this squad. The squad is truly above the Turkish league and at a level that can compete with some European teams. In a challenging environment like the Champions League, they might at least have a chance with good players. If Fenerbahçe qualified for the Champions League with this squad, I think they would perform much worse than Galatasaray.
Not the UCL mate, I mean it is clear that they are going to field day at their own league, and will be champions here in this super league, there is no doubt about that. There must be something seriously wrong at the club if they fail, like 5 injuries, a big problem, whatever, otherwise it is going to be a walk in the park for them and win the league.
The real trouble starts at UCL and looking at how they are not as good as most of the other teams, there is a serious possibility, not win it, but to be out of top 24 this season. They are nowhere near enough to be good to win UCL, not even like a quarter finals level of team, they are seriously not good enough. This is why I honestly believe that the best thing they can do right now is to keep grinding for more wins at their league, make more money, and keep building the team better.