This isn't very hard when you know some of the most genius strategies in human history were incredibly stupid, circumstantial events that led to victory by sheer luck of that strategy working.
Case in point: Tsun Zu's rival defended a city with 10 men against Tsun's army of hundreds by disarming his own soldiers, dressing them in plain clothes, INVITING Tsun's army to come in, and it only worked because Tsun knew the guy was an ambush master and thought "if we attack the city he's inviting us into, we will die." and left without even trying ON THE BASIS OF HIS RIVAL'S REPUTATION AND NOTHING MORE
Another example: Tsun Zu, on being told his soliders were out of arrows during a battle against a city across a river from them, had his men craft scarecrows, put them on a boat, send it out on a line, leave it there for half an hour, then pull it back in and used the arrows the enemy had fired at the boat to restock their own ammunition. It only worked because it was foggy and the enemy couldn't tell the difference between the scarecrows and actual soldiers.
Stupid things like that work INCREDIBLY WELL if the circumstances favor them, so you really don't need to come up with some multi-layered, Shikamaru-esque strategy. You just need to come up with a strategy you like for the characters involved, then write the circumstances (weather, environment, individuals involved) to favor it enough that it works.
