I learned to fly at Welshpool (f/w that is, not rotary). 1500 ft circuits, because of the hills!!! And you still turn final at 500 ft. I thought it was normal to bring back the power in the turn on to base, and to find it very difficult to lose the height before turning final. It isn't so bad in tomahawks, which I learned on, but in Cessnas!
Now I descend a little on late downwind, while still being careful of the hills. But I wouldn't teach a student to do that, not at Welshpool; you just don't have enough margin for error. So I suppose what I'm saying is that there are lots of different ways of doing it, and it doesn't have to be done by numbers. But initially, that's probably the esiest way to learn.