The bragging has nothing to do with the team but the fans and it's normal for them to feel confident. Ronaldo is delivering every time he has been called upon and it is left for others to chip in. It was a terrible match yesterday and the red card was silly while the back pass was annoying. As you have rightly said, they need to stop relying heavily on Ronaldo while trying to push themselves too but it's expected when you have someone of Ronaldo's calibre in your team. Same way they relied heavily on Bruno last season until Cavani came to chip in his bits.
Ronaldo would always be the go to guy, just see how Chelsea are set up too. Lukaku is at the heart of things and he is delivering but like you said, they also need to get goals elsewhere else they would be in for it but I believe both teams are capable they just need to do more.