P.S. - Thing to remember about fursuit head sizes is that not only does the foam and other construction materials make the head look big, but also the style, pattern, colors, pile length, of fur used can give the "impression" of a much bigger head than what is there.
For example, if a fursuit head has a large mane of fur (Like a lion.) or shaggy fur, etc., then that is going to give the "impression" of a fursuit head being much bigger than what it is.