That's impressive, but I can't understand how either of these companies are happy with that situation. It's like trying to argue a polygamist can be fully dedicated to both families.
Imagine going from 1 high pressure 8 hours job to another with only a 2 block walk between them, maybe lunch. I don't know, it sounds like overload to me.
Unlike Dorsey, I have never attempted to maintain that schedule over the long haul, but over periods of time at least, it is not as difficult as it sounds.