Good comparison, although I’m not sure that I would blame the Battle of Chosin Reservoir on McArthur. I don’t think MacArthur was to blame for the Chinese entry into the war. I think they came in because they knew that Truman was exceedingly fearful of getting involved with them. After all, it was Truman and his administration that helped give China to Mao in the first place.
The Vietnamese War turned into another Democrat war that the leadership were unwilling to win. We did, at least, save South Korea, but even though we won the war, we settled for the status quo ante, and gave the North Koreans a victory they scarcely deserved.
That reluctance to fight later led to Vietnam and the loss of much of Southeast Asia—another Democrat war that they started but refused to win.