TWENTYNINE PALMS, Calif. — Sitting around a plastic folding table in a dusty tent, a half-dozen officers of the Hawaii-based 3rd Marine Littoral Regiment took a very short break from days of fighting on little to no sleep. The war, they said, was going well. The unit, newly created and innovative in nature, was facing its toughest test yet — a 10-day mock battle across Southern California, where a series of military bases played the role of an island chain. Though outnumbered by the regiment it was fighting, the team…