I suspect that this group represented the entire hideout. There may be traps or guardians tied to a location left inside, but otherwise I think it we should be fairly safe to continue exploring. I think its extremely risky having the wizard as a captive. The hobgoblin or that last human are much safer prisoners. Considering how close we are to the town, I think its reasonable to return there after a short rest and questioning these prisoners. After delivering them to the authorities in town, we should return here to finish our exploration.