Of course they're going to be different.
These were the prototypes that would lead to the adjustable rear sights of the future...
It won't take much beyond ammunition and time - and consistency - to figure out your Schofield, though.
Try several different types of ammunition and bullet weight - you'll notice that your revolver will group tighter and to your point of aim with practice.
Once you've found something that works well for you - stick with it.
Fixed-sight revolvers can be adjusted by judicious filing.
Good Luck.
Vaya,
Scouts Out!