Maintaining distance in Shorinji Kempo's Tenchiken Dai Ichi Hokai

When performing the Hokai (pair form) Drills of Shorinji Kempo we are often taught that the two kenshi should remain along the same line on which they began.

Is this possible to do correctly if the two kenshi are of different reaches/heights? I would have thought that because the Kihon Ma’ai (optimal striking distance) for a kick from a taller person is much less than the Kihon Ma’ai for the punch from a shorter person this Hokai could not be performed correctly on a line at all in this situation.

That said I have seen instructors criticise kenshi who end the Hokai clockwise or anticlockwise of their starting position.