In contemplating the apparently vast human thirst for violence, it has occurred to me that gladiatorial combat might serve as a substitute for the entertainment aspects of war. But it may be that the more important point of war is precisely to inflict it on the unwilling, the innocent and the helpless, in which case that wouldn't work.
I am curious as to exactly why the Germans disliked it. Tribal people often engage in fairly rough sports, although maybe not as rough as those the civilized favor.