Memory and nostalgia are two different things. Willie Johnston was the darling of the crowd, but I remember Ray Wilson writing an article saying how frustrated he was playing behind Willie. He would overlap up the pitch to give Willie an outlet, but often had to run the length of the pitch after Willie tried to beat three players and lost the ball.
It's the times he beat three players that we remember.
I am going to be contentious and say that Diangana has the ability to be better than Willie. I am not saying he is better, or will be better, that's in his own hands, but he has the ability to be better.