I can't say enough good about the incredible interaction that I have seen between a redfin pickerel and an Anguilla Rostrata (American Eel). They literally work as a team hunting a bunch of Rosey Red feeders. These eels are nearly impossible for the worst fish keeper on Earth to unintentionally kill.
At less than $2 each, they would make tremendous tankmate(s) for your pickerels. Just make sure that you quarantine them thoroughly before adding them to the pickerel tanks.
