I believe that there has to be some room for stratification among your customers with high risk factors. There are some that are very obvious - like private ATM owners (those that can replenish are higher risk than those who can not), MSBs (agents of Money Gram are less risky than registered check cashers), NRAs (a Non-Resident alien from the UK could be considered less risky than an NRA from the Middle East), cash intensive businesses (those who you have banked for 25 years could be less risky than a new cash intensive business). You should be able to identify high, moderate, and low risk customers among each high risk group. This stratification can be used to schedule EDD reviews, obviously those that are more risky would be on a more aggressive schedule than those with a lower residual risk. To make this work though, you need to make sure that you document your reasoning for the stratification and that you have appropriate monitoring that will allow you to recognize changes in behavior among these customers that may change their residual risk.
I have gone down the road of reviewing all high risk customers X number of times a year and it can be a huge waste of resources reviewing low risk NRAs every quarter. Again, documentation is huge part of being able to defend these decisions to your auditor and examiner.
Knowledge is knowing what to say. Wisdom is knowing when to say it.