That's a really good question. Maybe we could open new thread becasue this is slightly offtopic.
Not only these projects but he's also scheduled on Prey.
http://www.eurogamer.net/articles/2016-06-13-prey-2-resurfaces-with-arkane-austin-in-chargeI don't know how he manages his time?
It believe that
time managment and
creativity is the key of the success.