Og, King of Bashan

How can we accept what the Torah says, that his bed was nine cubits long? Even if we accept the words of Maimonides in the book of Morah Nebuchim, that the length of the bed could be one and a half times the length of the person sleeping on it (although this seems exaggerated to me, since today the length of beds is about two meters), then a height of about three meters is almost impossible, and even if we assume that he had some illness that caused him to grow so tall, most of the tallest people needed crutches and the like, so why did God tell Moses not to fear him? What is there to fear from a person who needs support to walk?