I don't think you'd need absolute equality, influence, or perfect agreement, you'd just need it to facilitate somewhat voluntary cultural diffusion to decrease

I don't think you'd need absolute equality, influence, or perfect agreement, you'd just need it to facilitate somewhat voluntary cultural diffusion to decrease the level of conflict. In the context of the thread, it's historically accurate that this was already present in some ways during the centuries preceding Canada and the US' founding, but fell apart quite dramatically.