Thought I was on the wrong site when I came across this interesting article as its usually guess the crowd on here.
The simple answer is yes.We have introduced diets, better training methods and an analyst so this would be the next logical step.
Not sure of the evidence re sports psychologists improving performance but certainly they are generally accepted as being useful.
Of course Evans uses sports psychology without being a psychologist but I doubt that his methods are evidenced based!
So yes for the reasons you have outlined..it would be worthwhile Im sure.