The Japanese Army had many armies .
The U.S. Army only had ten at Japanese Army 's peak , with the 4th Army , the 6th Army , the 8th Army , and the 10th Army being in the Pacific Theater .
The Japanese Army had many armies , but the U.S. Army only had ten at its peak , with the 4th Army , the 6th Army , the 8th Army , and the 10th Army being in the Pacific Theater .