That's BS. Practice with a weapon as similar to the one you fight with as possible. That way, when you get to the real fight, you are comfortable and familiar with it in your hand. It's like training for Vietnam jungle and then shipping off to Iraq.
What you should practice against (and what you're trying to say) is to make your opponents as varied as possible in practice, or preferably (extension of the above principle) as near to your actual opponents as possible. cf. Sun Tzu: "Know thyself, and know thy enemy, and of a hundred battles you will be the victor. Know thyself, but not thy enemy, and even will be your losses and victories. Do not know thyself, and wallow in defeat forever."
The interesting thing about that particular wargame wasn't the communications, but the blue team "unsinking" a carrier that had been taken out by a massed small boat attack. Submarines...and targets.