This makes sense. I haven't considered the act and I imagine he can certainly incline towards a particular character type with it. Certainly convincing and I can lean towards ESTP with that. My initial thoughts were more on that his Ni wasn't very clear in the common typing of NTJ and wished to refute it.
Biographies work well for typology. Autobiographies are best. Ni is not only not clear, it is invisible. It is the exact opposite of Simon Cowell. The only other type call I would even consider is ISTP - except he's not that. Se is Simon's dominant function as revealed by his lifestyle.
"I absorb energy like a sponge everywhere I go. It allows me to see the world and my purpose in it." Zak Bagans, Ghost Adventures (INFJ)
"I don't believe in guilt, I only believe in living on impulses"
"Stereotypes about personality and gender turn out to be fairly accurate: ... On the binary Myers-Briggs measure, the thinking-feeling breakdown is about 30/70 for women versus 60/40 for men." ~ Bryan Caplan