When you see a score that's lower than you expect, it's good to first check that the test protocol was followed correctly and the person was standing as still as possible. Even small eye/head movements can be detected by the scale. More information on testing properly can be found here.
If the test was performed correctly, remember that the Stability scale is designed to capture the full range of human capability. Scoring 10/10 is very rare, and likely only seen in professional balance athletes who do many hours of high level balance training daily (dancers, acrobats etc)
Balance, like our muscles, adapt to what we make them do frequently. Many people in professional settings spend their days looking after others, working long hours, possibly impacting their own time to take care of their own health, exercise or get good quality sleep. This will likely show in their balance score.
A 'moderate risk' doesn't make them frail or likely to fall imminently, but it does show a possible decline in their postural stability control. You may be interested in a recent study that showed that falls in middle age are surprisingly high, they just don't get routinely monitored in the way that older adult falls do.
Remember - fatigue from even 1 night of poor sleep or a hard workout will also impact balance in the short term. Encourage your staff to experiment with their own balance to see what affects them the most. It's never too early or too late to learn.