Yeah. The intention isn't to have both loaded simultaneously, but in the event of a stoppage/breakdown, they can both be loaded on different levels. I'm fairly positive these are all the places trains can stop at:
First Launch
Second Launch
Brake Before Hagrid's
Third Launch After Hagrid's
Fourth Launch
Fluffy Brake
Reverse Launch
Drop Track 1
Drop Track 2
Final Brake Run
Add in a train at load and one at unload, there's all 12 trains.