It is interesting to pick on an example like the Battle of the Bulge. To put those men, on both sides, in the field was an enormous effort of collaboration. We can say it was doomed from the beginning, in hindsight, but it was very dangerous at the time and took enormous efforts to disengage troops and redeploy them. Patton's redeployment must be one of the greatest organisational feats in history.

At the beginning of the Battle the weather was terrible, stopping the normal collaboration with the air force. When the weather cleared, collaboration restarted, and both arms could work together much more effectively than the army alone.