i've always found it odd that there is such a term as "over qualified", after all in school, they have always told us to have as many qualifications as possible. i really don't know why you worry about having too many qualifications though, everyone comes from different backgrounds and would be trained the same way to have the same end result.
i didn't know it takes 4 years for a phd by the way. one thing though, would you be called dr or capt in the future if you had a phd as well?