It's all dependent upon the different airspaces the flight plan gets granted permission to traverse. Even on the best day there is no clear direct route. Permissions will be granted or denied on an almost daily basis so the actual number of tankings will vary. When they are allowed a more direct route the number, obviously, would be less. Working only on the basis of continuous flight through international airspace only and neutral weather, (no head or tail winds), the answer to your question would be 17 for the Tornado, 22 for the Harrier and a mere 14 for the Typhoon. Now, this assumes that the Suez airways are closed and the trip has to go all the way around Africa. If you can sneak through the Suez "gap" then the trips, (again, assuming neutral weather), are significantly reduced. It then only becomes a function of particular airframe's fuel consumption. There are "hot frames" and "cold frames" and their speeds and fuel efficiency vary quite significantly, as I'm sure you know, which will also affect, to a lesser extent, the number of planned refuels.
So... Which scenario are you interested in? Do you have a specific route in mind or are you just looking for a direct flight like the Americans would do with their stealth kites? This isn't just a simple A+B=C thing you know.