The 7.2 might have a front noodle with a "safety feature" -- in the ferrule above the noodle itself where the cable feeds in, there might be a spring, which supposedly helps riders avoid jamming on the front brake, giving more progressive brake application. This could be messing up adjustability on the front brake and the shop is merely trying to get front and rear to match. The 7.5 does not have this feature, which is why the brakes feel a lot better...