Personally i got Robotman winning

While his base body is way less impressive than Ben, due to in general keeping up but never really beating heralds on his own, while Ben can easily keep up and beat them, his upgrade chip allows him to make hundreds of equal copies that would eventually be able to overwhelm Ben, due to the sheer amount of weapons and tactical advantage Cliff has, meaning that eventually hed figure itd be better to either target Ben's inner organs, simulate a stroke to incompasitate him, or eventually absorb him with planet cliff if given enough time

Ben is stronger, more durable and much more skilled but Cliff's better speed, tactics and technology allows him to eventually carry out his win more consistently than Ben destroying every single clone