There are many forecasting techniques available. The goal is not see into the future, but to see the likely distribution of outcomes that come from decisions and sequence of future decisions.
Rumsfeld & Co had idea of what they wanted to happen, and then they twisted everything to justify it. That's just being an idiot. Rudimentary expert-opinion forecasting would have helped. Expert opinion was specially avoided or ignored.
It's true that "amateurs" can consistently beat "experts". But not all amateurs - only some. This suggests to me there is true prediction expertise, but our system that attaches labels of "expert" does not select for it.
Prediction is very much a skill and some people are very much better than others. We just don't regularly measure or select for it explicitly.
Many similar and more advanced techniques have been used in the military and business for ages. Training exercises , simulations, games, cross-impact analysis, policy capture analysis, scenario methods etc.
The war games I'm thinking of are those what flag officers and staff do in RAND and other places. For example, they bring in diplomats and other outsiders to play the opponents. Or they may be pen and paper games (spreadsheets) scenario analysis where sequence of actions are played out and consequence of every decision are updated into the environment.