One could say that it was the South which benefited from apportionment since 60% of their slave population, which had no need for representation in Washington since they were property and not citizens, was counted when deciding congressional representation.
One could say that. If one does, one should be prepared to explain what benefit they got from having fewer Representatives in Congress. While not considered "property", the Northern states had substantial numbers of un-naturalized immigrants that were not citizens, but still counted fully as residents in the census.
And so the North agreed to a term that provided absolutely no benefit whatsoever to themselves? Oh, but Wait! They wouldn't have gotten a deal otherwise, so apparently whatever benefit they received was a consequence of the Deal they made! (It was continuing independence from England. That was their benefit. )
But you make the argument that the North would have been far better off not to make such a deal, and i'm inclined to think the South certainly would have been.