The 100 American advisors in Korea,[5] working under the auspices of the Department of Internal Security (DIS), were reassigned to PMAG at this time, and the unit's roster was expanded.

New Commanding general of Eighth Army, James Van Fleet, was not fully satisfied with the progress of KMAG and although he thought Farrell had done a wonderful job as KMAG chief, he felt that Farrell was “completely worn out and needed a change.”[7][8] Van Fleet requested highly qualified troop trainer, Brigadier general Cornelius E. Ryan, a former commander of 101st Airborne Division, whom he knew from his previous assignment in the United States.

[7][8] He developed strong relation with his counterparts, generals Lee Chong-chan and Paik Sun-yup and worked together on plans to make a new army.

Under his experienced direction, KMAG then inaugurated a series of training and organizational reforms that laid the basis for a Korean Army capable of fighting the Chinese on more equal terms.

[7][8] Dr. Shiela Miyoshi Jager of the Strategic Studies Institute has supported using the highly successful KMAG methods as a model for the Multi-National Security Transition Command - Iraq in its development of the New Iraqi Army.