No Canadian lawyers here, just wanted to give you extra support.
Elementary school in a traditional public school setting (USA) has been mainly social. We think the teachers are not trained at a high level at all. They do not even realize how under-educated they may be.
Cluster is happening for Middle School and just in time. We can tell that the children, pre-pre-teen, are already starting to get meaner, tougher, how ever you want to express it.
From our experience, we look forward to never having to be in classes with or work with those folks ever again. Onward and upward. So, advocate as hard as you can for the cluster or we would probably do research and move to a better district if at all possible.
The more sensitive the child the harder it is on them to be grouped altogether year after year.
I don't think the teachers realize that the high-IQ people prefer to work together and we don't think the other people miss us one bit.
In fact, when we moved to the neighborhood we are still in now, one of the neighbors told us they can't stand 'book people.' Needless to say, no close ties there.
Be careful about jealousy. People can get very negative when they perceive a large difference in intelligence. Just facts (don't want to be negative, just honest). The jealousy ( or how ever to categorize the reaction ) can lead to physical and / or verbal abuse.
