The are many matters about which Rishonim disagreed, Therefore some were right and some were wrong. If they had all agreed on everything, there would be no need for Achronim to carry on the debates. The question is therefore a classic example of a “Klutz Kasha” since on its own terms the answer is obvious.
Come on! Elu V’Elu means they were both right (just don’t ask me how)