If you want to lie to everypony else, that’s one thing, but you’re not about to lie to yourself. You do not have split personality. These ideas are just every possible angle you can think up at the time.
Besides, it would be Schizophrenia, not split personality, which isn’t even the proper name of that mental disorder.
Double besides, all of you are already hiding. And how are you supposed to just blackout on command?
You ask if a diplomatic approach with the giant is at all possible, to which Amy and Princess flat-out refuse. It’s not just a giant, it’s a shadow. Those things attacked without provocation and stole something valuable from Amy and Princess. They need to get back what was stolen. But you’ve no way of knowing if that giant has whatever it was.
Amy remarks that what was stolen wasn’t necessarily valuable, but Princess disagrees. The two begin to argue, but with mind enough to keep their voices down.