Who was the tougher World War II enemy, the Germans or the Japanese?

Yesterday I was reading the transcript of comments Gen. J. Lawton Collins made at Fort Leavenworth in 1983. "Lighning Joe" Collins was one of the few generals to fight in both the Pacific and the European theaters in World War II, and to my knowledge, the only one successful in both. (Generals Eugene Landrum and Charles Corlett, not so much.) So I was interested to see Collins conclude that the Germans were better fighters:

They were radically different. The German was far more skilled than the Japanese. Most of the Japanese that we fought were not skilled men. Not skilled leaders. The German had a professional army. . . . The Japanese army was very much like ours in a sense. They had a small corps of officers who were professionals. But the bulk of their people were not professionals in the sense of knowing their business and so on. They didn’t have the equipment that we had. They didn’t know how to handle combined arms-the artillery and the support of the infantry-to the same extent we did. They were gallant soldiers, though. They fought to the end and you had to knock them off-that was all there was to it. And we had to do that right on Guadalcanal. . . . The Japanese were very gallant men. They fought very, very hard, but they were not nearly as skillful as the Germans. But the German didn’t have the tenacity of the Japanese."

Tom again: Still, I think the Pacific war, conducted on remote islands where the enemy would fight to the death, probably was the tougher fight, even if the foe wasn’t as skillful or as well-equipped.