Since the CPE2000i uses a sync cable for parallel operation, I would expect that it could only sync-up with one of its own kind. The Honda and Yamaha synchronize without the use of an extra cable, so they would possibly synchronize with an already-running CPE generator. The Hondas AFAIK stand alone with an output voltage well above 120, so if one of them were paired with another generator I'd expect the Honda to carry all of the load until its output voltage was pulled down to 120, which occurs after it is supplying more than its rated continuous load. This is all speculation of course until somebody tries it, risking the unintended consequence of breaking something in the process. Based on what I know, the Champion-Honda combo would in the best case be undesirable, and in the worst case send up a smoke cloud.
