A regular Credit Exposure Review is both a superior organizational practice as well as a way to scrutinize NPAs on a regular basis.
This would involve classifying loans as good, potential to go bad, very bad etc. Similarly for an insurance company, there may be a need to bound the total exposure to an individual.
In either case, de-duplication would ensure that all accounts are merged and a total picture is obtained.
If only an account level picture is taken, divergence could sneak in, and an individual may build in the good category for one account and bad category for another account.