I like this feature of sniping enemies as sort of a strange detail/ minigame, then they just made as much of the gameplay as they could generic.
Stage: Battle of Echizen (Has to be story mode)
Difficulty: Hard (Or Chaos)
How To: Defeat Katsuie Shibata and Nobumori Sakuma within 2 minutes, then Snipe Mitsuhide from the east bank. Then protect all 5 of the pilgrims while they escape.
Supply Team Location: South West gate and they head to the gate north east of Mitsuhide's loaction
Tips/ General Strat: I'm not sure if you need to escape detection from Hanzo (After you snipe Mitsuhide), but it is possible to protect the pilgrims and evade him. Most of this is self explanatory, but make sure you go as far out of your way around Mitsuhide's camp otherwise they detect you.