Insurance for a global traveller based in the UAE

Hello Everyone,
I’m Anita (John’s business manager) and im glad to have found this community. It’s been a challenge finding good info on the web for business nomads. I’m looking for insurance for John - basically, a person who doesn’t intend on keeping a home base for more than 6 months. Currently based in the UAE, John is a keynote speaker who travels weekly around the world and never staying more than a week at max in that country. So an itinerary is difficult as it is based on upcoming bookings for some of the insurance options I have found (worldnomads, geoblue which is only USA based).

Can you offer me some well-needed advice please?