I hope the book helps your H (and you) understand himself better. My H scored 14 out of 21. Neither one of us likes an overstimulating environment, so we have fewer problems in this area. We don't find the same things overstimulating, though. For example, H doesn't find tastes and smells bothersome as I do, yet, he finds a cruise bothersome because of the crowds. I don't mind that.
I think it comes down to figuring out ways to cope with the things we can't avoid and avoiding the things we can. For example, hosting parties way overstimulates me, so I just don't do it. If it's something like that that I don't HAVE to do, I don't.