"No, twins have different personalities, or can. We and our respective alts have the same personalities, similar names in many cases, mostly but not invariably matching families out to varying distances, lots of weird coincidences - except they clearly aren't coincidences, it stacks up way too much to be coincidental, we just don't know why it happens. We found out when we went to pester the Amentan who was running things post-conquest about how he'd conquered our planet and he looked like yet another of my many brothers-in-law."