1969 Dodge Dart issue with installing axles after thrust block removal.

How do the splines get misaligned from each other just by having the axle ve been at this for decades and haven’t had it happen with taking it apart. They are loaded and don’t move easily.
Because you have to take the SG apart to remove the thrust spacer. If you don’t align the-cone and side gear when you bolt it back together, they will be out of line.