You're kidding yourself if you think it's going to be much more than that. Hell, there may not even be three upon open. Universal wants to be much more of a family destination. They aren't going to go around building a bunch of big boy coasters in their new park. Sure they'll probably have one like they have in IOA (Hulk) and USF (HRRR), but the fact that those are the only two big thrill coasters currently existing at UOR should tell you what to expect at Fantastic World.
Eventually that will probably be necessary for proper expansion. I just wonder if SeaWorld is actually going to be willing to spend about as much money as a new coaster would cost on a parking garage. Especially with their current situation where they seem to be keeping things pretty tight financially.