You have a heart for these animals, I know how you feel. If you are prepared to keep them for their lifetime that would be fine since they are eating. If it were me I would quarantine them and nurse them to health and make them a wonderful home like your other frogs have and just enjoy them. They are cuties! If you can't keep them then the responsible thing to do is euthanize them. I applaud you for ending their suffering at the hands of their kin, regardless the outcome.