All segments in a same row should have the same height, if not there is no way to fit them. In the first scene, Y Evenly is larger than Left/Right Sides. That's the problem.
I've attached a variation using two Sequences on Y, instead using Evenly. I also removed the Y Spline, and replaced it by Generator->Y Size and Generator->X Rotation=90. In this way is simpler to set the building's height.
Same problem with the X Evenly scene: all segments must have the same height.