[Darksheare]

Without personal knowledge, or having a good grasp of the entire situation, the thought that comes to mind about Chosin Reservoir and the Army and Marine units differing results is that it came about in the only way it could given the intel, thinking, and equipment on hand.
Neither group could support the other, it seems, and even if they could've tried, it would have been at higher casualties to each or the other.

May those that fell in that battle rest in peace.

[SAMWolf]

I seem to remember some critism about spiltting the offensive into mutually unsupporting routes.

Part of the problem was the terrain, another was, once again, over-confidence and then there was the failure of intepreting the available intelligence.