Simpson said: "He has taken certain things from Sir Alex.
"You can see the comparisons. But then after playing under him for so many years, he is going to take something from him.
"You look at the other managers who have played under him, and I believe they have all taken something from him too.
"Paul has certainly helped me a lot since he has been here, and he is proving to be a really good manager.
"For the first few weeks he told me just to settle in, and then he gave me my chance, and I am grateful for that.
"From what I've seen we have a good group of players here, there is a really good bond.
"It's thanks to that, the manager and all the staff I've settled in well."