Hi! Welcome to the forums! It all depends on how the phone is dropped, and of course, the height of the drop, etc. But you can for sure protect your glass phone with a clear case or any case of your choosing. Even slimmer cases do provide some kind of shock absorption support; although there are bulkier, more durable cases that will certainly provide more protection.
I have an Honor 8 which is entirely made of glass; and I'm using a clear skin case with it. It's had a few drops and bumps, and nothing has happened to the phone at all! I would recommend getting a tempered glass screen protector, as well; just in case. My screen protector does have a small crack on it that could have been the screen had it not been installed. Good luck!