In S02E09 of Marvel's Agents of S.H.I.E.L.D.,
it is revealed that Koenig guys are brothers rather than some kind of robots or clones. There are 13 Koenig brothers (out of which one is dead). All brothers are like twins except twin word isn't valid for them. Certainly, one mother can't give birth to 13 kids at a time.
How are they like twins?
Also, in the very end of last episode of season 1,
New Koenig in main base said exact words in exactly the same way as his dead brother.
How could that be for a normal biological twin?