Interesting. So only page managers (assumed to be unit leaders) can tag. Tagging is done by linking the picture to a scout's FB account, right? Isn't that identifying that scout by name and other FB info? Is that available for anyone on FB to see that picture?
If a FB group is private ("closed"), and a person is tagged in photos in that group, they cannot be seen by people who are not also in the group. In the way back of FB, you could notice this discrepancy when someone's profile said they had 100 photos, but when you clicked, you could only see 58—the remainder were photos that the person's friends had in private albums, or from closed groups, or that the person had specifically blocked you from seeing by putting you in a friends category then restricting that category from seeing certain albums (I, for example, have categories like BSA adults, BSA youth, aunties, co-workers.)
But, the tagged photos can be seen by people who are also in the group when they pull up the person's photos from that person's profile.
If the group is public ("open"), and the scout is tagged in a photo, anyone could see his tag on the photo by going to the group photos, and anyone could see the photos from his profile.
But, if the group is public and his profile is private, then a person could only see the photos from the group.
Because profiles and groups have varying options around privacy, there are a lot of combinations that depend on the interplay between the group settings and each person's profile settings.