Mark Sanchez was thrown into a good franchise with the Jets and he's been terrible
He went to 2 AFC Championships because he had a solid OLine, Defense and Running game which Smith Never had ever in SF. KC has that.
Rodgers spent 2 yrs behind favre and that helped tremendously you cant deny that.
He also attended McCarthy's QB Camp for 6hrs a day which helped him become a great QB.
Smith never had any of that till Harbaugh and he turned into a solid QB under solid coaching
Reid is good enough and KC cant ask for much more than that right now