How are the numbers alive? That experiment was abandoned due to failure. Then ceasar started a different approach of using kids and giving them drugs ti enhance their growth, even that was not successful with them being able to live for only 5 years. And they are even being called failures but are still alive. Sad plot.
When the opening spoiler again us, Kaido far behind and on Luffy way their are Big mom,Queen and King, people ask about Jack why he wasn´t their, now it make sense because Jack help up Kaido in the battle.