How would define a spine in a golf club? Simply put a poorly made shaft has usually 2 planes 90* to each other. One plane is stiffer than the other. When one plane has 10 more cycles per minute than the other it means one full flex difference between the 2. To make it easy to understand let's take a ruler as an example. Hold a 36 or 48 inch ruler (wood or metal does not matter)as you would hold a golf club with the flat(thin) side in the 12 o'clock position. Waggle the ruler and it will flex towards the target. The flexible part is called the NBP short for neutral bend point. The thin side is called the spine. If you were to rotate the ruler 90 degres and perform the same exercise you would barely get the ruler to flex towards the target.
There is hardly any spine in a steel shaft and it's not worth aligning them. Unless you're a believer in residual bend(warped shaft) a steel shaft will never have more than a 1-2 cpm when rotated in a frequency meter 360 degrees. Big waste of time if you ask me.
Graphite shafts are different. Of course some shafts are excellent and don't need to be spined as the frequency is the same all the way around the circumference. Mercury shafts and SK Fiber shafts come to mind and they are guaranteed +- cpm by the manufacturer. There are others out there. Most filament shafts are spineless and are very stable.
Do you need a frequency meter or a NF2 or NF4 to find out if your shafts are properly aligned. The answer is no. But you do have to have a solid vise and an excellent clamp. all you have to do is to clamp the but end of the club and twang it either vertically or horizontally. If the shaft goes straight up and down then the club is properly aligned or is at least stable in 1 of the 2 planes. If it wobbles then it needs to be reoriented.
Hope this unconfuses.