Generally that how most uniform systems development works. You have the initial prototype then issued for user trails. Those users cover a wide base of specialities to get as broad a perspective as possible. It’s actually kind like how drugs and Vaccines are supposed to be tested. You want as broad a range and background as possible to gage if the aspects of the product meet as much of the needs as possible. For military uniforms that means infantry, Armored crewmen, Aviation crews, medical, SF, staff personnel, trainees, Veterans, Males, females, Petite, giants,Skin types, Arctic, Tropical, dry, wet and more. To determine how durable, flexible, comfortable, capable, breathable, scalable, Tailorable, manufacturable, ergonomic, protective and appropriate the uniform is for actual long term. Even after officially being accepted and issued uniform often have new wear and modifications issued on a regular basis as input comes in. Like is the rank insignia better here of there. Should we add this or that because of issues here. Did the trousers rip or wear out prematurely because we should have added this. This new material makes it better because of X. And so on. Uniforms are in there own way a living thing, changing and evolving to match their organization and mission needs.