Now his unit is deployed in Afghanistan's Zabul province, a vital staging post for insurgents in southern Afghanistan, and the role-playing experience has paid dividends.
Recounting a recent clash, Hearn said his unit rushed in a blocking force to cut off the valley that was the site of the Taliban stronghold. Mortars were targeted on the expected escape route and airstrikes readied before fighting erupted.
"They (the militants) did exactly what we would have done if we were acting as OPFOR," Hearn said. The Taliban fighters were trapped, and a number were killed, he said.
But while the soldiers may be better able to predict how the Taliban will act, the battalion's tactical insight may not be enough.
The "Men in Black" — who get their name from their earlier roles as black-uniformed Soviet bloc troops — suffer from the problem faced by other U.S. and NATO forces in Afghanistan: They're too few in too large a place.