No, because there's no ceiling on what the more able kids can achieve. At the top end, you're looking at a more in depth mastery approach. So the concepts they tackle will be more catered to their learning ability. A child who is working towards expectations might not give you the answer to the same problem, but that doesn't mean they couldn't answer a problem tailored to their specific learning needs. So they can still demonstrate the skills of, say, problem solving, but in their own way. It wouldn't be fair on a child who cannot access the curriculum for a certain reason to expect them to be able to do the things greater depth children could, but it doesn't mean that they can't do something similar at a level they are more suited to. The cartoon below shows this perfectly.
You must log in or register to see images
I wouldn't place a ceiling on the higher ability children any more than I would the lower ability ones, each has their own strengths and weaknesses that they encounter in their learning. When considering pitching work to a class, I find it more helpful to think of it as depth of knowledge, rather than breadth of knowledge. Knowing all the times tables by rote up to 12 x 12 is great, but do they understand why 6 x 9 = 54? If they don't, what's the point in knowing it? Can they prove it? Can they show me a real life example where they might come across a problem? For lower ability children, it might that they show me how they know three goes into nine three times, using resources or drawings.
On the caning thing I saw, if you have to physically harm a child in order for them to follow you, you aren't very good at being an adult. Respect in children is born out of admiration, not out of fear. If you have to frighten a mind more underdeveloped than yours in order for it to follow instructions, ****ing quit whatever it is your doing, paint yourself silver and go and be a robot on the South Bank of the Thames. That applies to children and animals, by the way.