Enact a 7 year statute of limitations for collection of payroll overpayments to military and civilian employees that are the result of errors. The only exception to this is if the error is due to intentional misstatement or fraud.
Bottom line: go after the big stuff and get as much little stuff as you can within 7 years like the IRS. Then use the money you would spend going and trying to collect 20 year old debts to update your 50 year old systems that might not make as many mistakes if they were updated!