A fighting retreat makes a good clip and it is a bad sign. Somebody let an attack get far enough that stalling it was the best move left on the board.

In Escalation the reason I almost never pulled back is that a retreating army is the easiest one to kill. You are crossing ground you do not control with your damage pointed the wrong way. Committing was usually cheaper than withdrawing, even in the fights I lost.

The team game is the honest exception and I will give it that. If the ally actually turns up, the army that bought the time did its job, and what it was holding was never its own position to begin with. That only looks like a desperate gambit if you are still counting armies separately, and in a team game you should not be.