Just draw one single raililg for all. Its not simple, but the trick is - from the bottom of the stair - draw the railing on the first step -edge to the last step edge and get one other point to go on horizontally. You will have to try several versions to get it right and then you know it forever. Another possibility is first to draw a complete morphline-polygone in 3D and then let the railing follow.
AC5.5-AC27EduAut, PC-Win10, MacbookAirM1, MacbookM1Max, Win-I7+Nvidia