There is what de Lubac refers to as "the Christian paradox of man." We are truly open, by nature, to being made one with Christ - and - in fact even more so precisely by virtue of that union - we are truly made to be distinct persons. Perhaps it could be said that some saints reveal especially one of those truths, and some saints the other. Francis's distinctiveness in Christ is known to all. Dominic even more fully "decreases" so that Christ - and the saint - may "increase."
The idea that "we are truly made to be distinct persons" has some important consequences.
First, if we are made to be distinct, then if we were all perfectly what we were made to be (as we will be, God willing), we would all be different. My perfection is not your perfection.
This means there is no single idea of human perfection; the perfection of mankind, or rather of the Mystical Body of Christ, necessarily involves the individual perfections of individual men. Which means humans by nature exist in community.
Of course, you don't need a chain of theological reasoning to conclude that humans by nature exist in community. But the human community we simply observe is only a pale suggestion of the eschatological community of the Divine Family -- the Father, His Son by nature, and all His children by adoption, united by the Holy Spirit. For this Family to be perfect (as it pretty obviously will be), each member must be distinct, and therefore every member will relate to every other member in a unique way. It's a very dynamic picture, I think.
Suppose, though, that perfect humans weren't distinct. Then one would have the identical relationship with every other perfect human. And if one of these perfect humans happened to not be there -- happened to have died cut off from God -- who would know? What difference would it make, even to God. Divine perfection does not consist in infinite accumulation; the measure of the Divine Family is not in sheer number, as though it would be more perfect with eighty billion humans than with seventy-nine billion. (If numbers were the measure of perfection, there would have to be an infinite number of children-by-adoption, which is impossible.)
So when we are perfect we must be distinct if anyone is to care that we exist -- if, that is, we are to be lovable.