USB encoder with two four-pin inputs

[CaptainKoloth]

I recently nodded my Arcade1Up via ETA Prime’s amazing YouTube instructions. I have a USB encoder taking a joystick with 5 pins and with a usb out to the computer which has four pins. However, I have a trackball/dial combination that also has 4 pins. I’d like to be able to connect the trackball/dial to the computer using an additional encoder, which would require two four pin inputs (one from the trackball, one from the computer) but every encoder I’ve found online so far has one four-pin and one five-pin input. I need two four pin inputs. Does anyone know where to find one of these? Do they exist? Apologies for any terminology I messed up here with regard to the pins.