BBS is set 10 years into the past.
Zexion would look 10 years younger. How long did people actually think it took for them to turn into Nobodies? I always thought it was a couple of months or a year before KH1, considering they would have to ban Ansem, and have enough time to build up the Organization to at least Twelve members by the end of KH1. Which wouldn't take that long, so I go with the months one. I was expecting a kid form of him, so I wasn't that shocked. That's what I was waiting for, to see if he would really be that young.
And my Lord, how cute Ienzo is. Tawwwwwwwwww! x3 Where did they adopt him from?
On the other hand, the kid must be a genius to be prepped up for apprenticeship already. Talk about protégé.
But if Ienzo's 11 or younger in the past, and AtW's apprentices turned into Nobodies soon after, it doesn't make any sense. Remember, in the interviews, Nomura did say that Nobodies do not age.