I would use the last name as shown on the military ID as that should provide consistent results. 3 critical field are the SSN, DOB and last name. The next time you get a multiple last name like Cruz De la Hoya, try submitting it more than one way and see if it shows a hit based on the last name entered in addition to the same SSN and DOB. If you do that, let us know if it triggered off a partial last name or not.
My opinions are not necessarily my employers.
Rules and Regs minus Relationships equals Resentment and Rebellion. John Maxwell