The possibility of high-energy positively-charged particle beam splitting by means of a short bent axially oriented silicon crystal was recently reported in an experiment carried out at CERN SPS H8 extracted line with a 400 GeV/c proton beam. Here, we investigate more deeply such a possibility focusing our attention on the efficiency of beam splitting and its modulation for different crystal-to-beam orientations. New experimental results confirm the possibility of modulating the 400 GeV/c proton beam intensity in different planar channels by adjusting the orientation of the crystal. Furthermore, an analysis of the beam splitting efficiency vs. the curvature of the crystal was carried out through simulation, highlighting that there exists a bending radius for which the efficiency is maximal.