I used to have the same problem. Then I realized my hair is thinning, and any style haircut I wanted would never look how I expected due to thin spots. So I just have them shave my head. #0 or 1/8th inch. Go back 2-3 months later and repeat. Try it. If nothing else, it’ll grow our to about the length you want on top, then just have them trim the sides down.
Kingsize. Some of their shirts have a longer length option that adds an inch or two to the length.