No i don't mean children. I mean fusion without childbirth or sexual copulation. I mean if there's two 6 foot people and they fuse then they would immediately form a 12 foot person with both personalities combined into the fusion.
What are you trying to get at? People aren't made of clay. You can't just lump two people together to get a double sized person.
Think what you're asking, we are made of organs, muscles, bones and a host of other tissue with each person's DNA being different. Even at the cell level, how would you ever combine these into one person and not have tissue rejection?