You only need 1 foodbag/bear canister, first aid kit, kitchen(share 1 pan,1spoon,1windscreen , 1stove), water treatment, camera, shelter, knife, trowel, soap, sunscreen, map, compass.

If you are more into hike than camp, you can go with 1 puffy jacket / warm pants and take turns.

If you don't hike after dark, you can use 1 lamp. working together you can climb and descend peaks with a shared lamp, staying on trail shouldn't be that hard.