

When I was in high school, I volunteered for a couple of days in a special ed class, which, I guess by definition, contained people with sub-100 IQ (sub-70, even). I guess that fits your specifications. One thing I remember observing was that the girls were more capable of stringing together coherent sentences than the boys.
Also, a couple of years ago, I worked as a school bus driver for 3 months while looking for a tech job. There seemed to be much more variance in intelligence among my colleagues than I was used to: some seemed to be just as smart as most of the ones in my previous tech jobs, but others, while they were generally nice enough, seemed to fail to grasp basic concepts or retain information very well during the training.

Even in the context of the game, at some point, Batman is asked something like, “These are all criminals, should you really be helping them?” and Batman responds by pointing out that some of the inmates are political prisoners. Which is very applicable to real life, given how corrupt almost all justice systems in the world are.