Good post I have the same concern. My girth starts at 5.25” behind the head and goes to 6.25” at the base.
I am nearly the same, right around 6.25” at the base and a little more than 5.25” at the glans. I don’t see it as a problem. Being a little less thick at the glans makes fellatio easier but you still have ample maximal girth for vaginal intercourse, and tapering down to a smaller diameter at the head makes insertion easier for women who are naturally tight.
If the vagina is most sensitive within an inch or so of the entrance (as is generally accepted) and if women are most responsive to the stretching effect of girth, then it would seem to me that having maximal girth at the base is where it will do the most good at the same time you are maximally inserted to provide indirect clitoral stimulation from close pubic contact.