Ronda wins fights because she relies heavily/entirely on her judo skills. These skills are ingrained in her because she has been doing judo for 20 years. She doesn't need to be mentally on point in this fight because everything she does in the cage is second nature to her. Whether she is mentally ready or not isn't going to matter because if her judo works she wins and if it doesn't she's screwed. Holly is the perfect opponent to expose Ronda but Nunes style is actually pretty favorable to Rousey. The only way Rousey's mental state plays a role is if it has effected her physical fitness level and by all accounts it appears Ronda is in good shape physically. I think Rousey takes this fight and makes it looks easy.