It's not a question of whether the Schofield is inherently accurate or not, it's a matter of sights. Actually, of all the model 3's, the Schofield has the most visible. Look at a Russian or later S&W breaktop, the rear sight is tiny.
Just because the Military used a "point and shoot" technique from horseback for combat doesn't mean the revolvers were not accurate enough for target shooting.
For quick shooting in a CAS match, the larger notch is about all you'll get time to see. If you want to check the POI aganst the POA, try it on a paper bullseye target, carefully aiming, and see where it shoots.