I've never done a report like that, but maybe you could try this?
In the Loan account subreport, count the number of loans for that person, (excluding the filter one, which I presume is a parameter). Or count tham all and take one off at the end.
Put that count into a shared number variable 'loan_count'.
In the Savings subreport, count the number of savings accounts for the person, and put that into a shared variable 'save_count'
Pass these counts to formulae in the main report group footer.
Create a formula that says 'Y' or 'N' if your conditions are fulfilled for that person, based on the counts.
You can then count the Y to see how many people you have overall that match your conditions.