#2 His strike partner

While Ronaldo's efficiency as the focal point of an attack is not in doubt (his performances in the Portugal national team emphasizes that), what cannot be denied is the role Benzema has played in his goalscoring prowess over the years.
Karim Benzema was signed in the same summer as Ronaldo by Real Madrid, and the Frenchman arrived with a burgeoning reputation as a 21-year-old scoring machine.
However, Cristiano Ronaldo is very much the superior player of the two, and Karim Benzema unselfishly sacrificed his personal gains over the last nine seasons for Cristiano Ronaldo to flourish.
Karim Benzema was the out-and-out striker at Real, but it was not an uncommon scene to see the 31-year-old drift out wide during counters and supply crosses for Ronaldo to finish off. It, therefore, came as no surprise to find that Ronaldo was one of Benzema's fiercest defenders when criticisms of his low goalscoring returns arose.
At Juventus however, the situation is undoubtedly not going to be the same. Ronaldo's arrival has already caused an upheaval in the club's attacking department, with Higuain going out on loan to AC Milan.
Ronaldo is likely to find himself partnered by Croatian international Mario Mandzukic over the course of the season, and this could have an impact on Ronaldo's productivity, as, at 6ft 2in, Mandzukic's physicality means he also plays as a target man in the opposition box.
Signs of their unsuitability arose in the club's 2-0 victory over Lazio, where Mandzukic and Ronaldo continuously went for the same ball, leaving Ronaldo to drift out wide and turn provider.
Ronaldo is undoubtedly the symbol of this Juventus team, possessing a vastly superior skill set to everyone else at the club, and his wages adequately reflect that (his wages make up about 40% of Juve's entire wage bill).
Hence, Massimiliano Allegri is bound to build the team's play around Ronaldo's strengths. However, whether Mandzukic can seamlessly adapt to Ronaldo's playing pattern remains to be seen, and a failure to do so would result in a depleting of Ronaldo's goalscoring returns.