You're implying that a supporter is incorrect in his/her observation that we were better/looked better as a result of Fernandinho being on the field, rather than Rodri, because the goals and more chances came whilst Rodri was on the pitch.
Thus, you're assuming that the correlation between the events are, in whatever part, credited to Rodri's presence. You've taken a bunch of variables and deduced a cause and effect relationship between them, based on an observation. That is the definition of someone thinking correlation equals causation.
You're wrong, as you usually are.