I don't think you'll find this argument being raised amongst aviators, from any of the services.
In my experience this topic is only ever raised by folk who have no idea of the different roles that are carried out by their "Air Support" and how they dovetail together.
Luckily, these aren't the people who can actually effect change. By the time they get to such exalted positions, the question has already been answered.
Yes I'll agree there is a bit of overlap, but only between RAF & Navy, and RAF & Army. I can't think of any circumstances where Navy & Army Aviation tasks and capabilities overlap. I personally would rather have a slight overlap in capabilities than a gap
