Obviously Ganon can punish you for whiffing. That's why I said put hitboxes in his zones, not attack where he is. There's a difference. Zoning entails limiting your opponent by shutting down one or more of their strongest options. You can do things like jab and d-tilt barely at and perhaps outside of their tip ranges in order to confirm Ganon's inital retaliatory responses (such as retreating, approaching, or jumping). Regardless of what he chooses to do, you haven't overcommitted, and therefore you can react with impunity, transitioning into attacks that require more commitment like SH fair/nair, since you would at that point have a better grasp of Ganon's immediate options and know that you can go for something with a higher reward, and in that instance you would be better assured of its safety.