[distortedsignal]

How do you know which conflict you're going to fight next?

Each of these commanders may be better suited to a different conflict. The commander who is competent in one conflict may be a buffoon in a different conflict.

Even winning battles doesn't necessarily set up a commander for success. If your enemy changes between conflicts (say, going from a near-peer adversary to an insurgent adversary, a-la-Gulf War 1 -> Gulf War 2, or insurgency to near-peer, a-la Russia-in-Chechnya to Russia-in-Ukraine), radically different strategy, operations, and tactics are required.

I think this goes a long way to explaining the old saying "everyone prepares to win the last war." It boils down to "this guy did good last time, he'll do good this time too" when what helped him the last time is a very specific way of thinking that is not applicable now.

TL;DR: Responding to Change over Following a Plan