But Heihatchi's level 3 is a screen clearer, and his level 2 is similar to Parappa in execution.
What are you getting at though? We already know this. The point still stands that sometimes it's better to go for level 3 if you think you'll need to cancel someone else's super out. If you're Heihachi against PaRappa, your level 3 will save you from PaRappa if he activates his level 2.