[5] Guerrilla leader Robert Lapham said the McClish was "sometimes criticized for his alleged lack of seriousness", but "got on remarkably well with Filipino civilians and established advantageous relations with them by being affable and approachable."

Major (later General) Stephen Mellnik and Commander Melvyn McCoy, escaped prisoners of war, were helped by McClish and were favorably impressed by him.

[12] On 20 November 1942, McClish, a major, and Captain Clyde Childress met with Wendell Fertig, a self-proclaimed general officer.

Although the siege was a failure, it apparently won credibility for the guerrillas among the local people as fighters, not just refugees hiding in the mountains.

[15] [16] Also in 1943, when coastwatcher Chick Parsons arrived on Mindanao to carry out MacArthur's mandate to focus on intelligence gathering, McClish provided him with personnel for his coast watching station, fueled his launch with diesel distilled from coconuts, and mounted a .50 caliber machine gun on his boat.

[17] McClish and his chief of staff Clyde Childress had a rocky relationship with Wendell Fertig, the self-proclaimed brigadier general in charge of Mindinao guerrillas.

McClish and Childress were among several American officers serving under Fertig who requested transfers from the guerrillas to regular U.S. army commands which became possible after the U.S. invasion of the Philippines on 20 October 1944.

[18] Robert Lapham described McClish and Childress's opinion of Fertig as "paranoid and consumed with personal ambition, not to speak of ungrateful and discourteous to them after they had made it possible for him to move his headquarters to a safe location.