So yeah, saying the moon is 1/400 the size of the sun is laughable.
I personally think that the word size is ambiguous enough not to imply a volume ratio. Actually when the context is the apparent size of an object in the sky, I imagine that the diameter is the first thing that comes to mind. (Or to be more exact the second thing just after the apparent area of the object in my field of view which is directly related to the diameter.)


I mean it was often his style to transform into some sort of animal (e.g. bull or swan) to lure women in with his beauty. So he might have spent some time as a squirrel too and his pecker was probably any size he wanted. A bunch of fabled beasts come from such adventures like the minotaur from his bull phase with Europa.