Beautiful, just beautiful. This! This is why we're spending all that effort unwrapping those scrolls that Vesuvius tried to bury for some reason all those millennia ago.
I don't have any actual brothers but I do have friends who might as well be brothers. Are my balls both unique or is one of them identical to that of my bros?
Plato says we all have imperfect copies of the ideal testicles, but Aristotle says you shouldn't rely on theorising but test scientifically. Only by a thorough mutual examination of all your friends' testicles can you really know.