the more inclined the bench the more your shoulders are worked…a vertical 90 degree bench would be a overhead shoulder press and a flat 0 degree bench would be a flat bench “chest” press…why did you say yours was more shoulders and his was more chest?
i like to set my incline less than 45 degrees to keep more of my chest involved…i rarely do flat bench however…i just prefer incline db and dips as my chest exercises…and decline narrow (used mainly to hit my triceps)