I always adjust drum brakes with the wheels on. I adjust them so that there's enough of a drag on the wheels so that I cannot spin it a full revolution. That's noticeable drag. Maybe heavy handed for some, but it works very well for me. Once everything moves around a little from the weight being on the wheels and a short test drive, they are about perfect. Since the rear brakes on a drum system have a lot to do with pedal height, I want them as tight as I can get them so there's no looseness. Been adjusting brakes like that since I was about ten years old when I was taught how and never had a problem.