The other two were much inferior, more like typical gangster gunmen. Jimmy took out the first person who had that gangster gunman style.
The agent who was shot earlier was hit by one of the sharpshooters. He took advantage of the moment when the agent changed the magazine and came out to suppress the enemy, firing at the precise timing. This sort of person couldn't be left alive, otherwise, they would be too big a threat to others.
Jimmy focused his attention on those two. He poked his head out and fired a shot before quickly retreating. There had been a chance earlier, but when Jimmy raised his gun, that expert had already ducked away. The expert just barely showed his head, without firing a shot, making him seriously suspect a kind of Sixth Sense danger detection.
