Howdy
I don't have an Uberti Schofield, but I have a couple of originals.
Yes, the grip on the Schofield, as well as all the other Smith and Wesson large frame #3 Top Breaks is different than a Colt or a Ruger.
The hammer spur is further from the grip in all the S&W #3 Top Breaks, and the Schofield is no different. This means when shooting one handed, one has to reach further with the thumb to reach the hammer spur in order to cock the hammerr.
Here is a comparison photo showing a Colt and a Schofield. You can see how the Colt hammer spur extends further back, making it easier to reach when cocking the revolver one handed.
How long does it take to get used to? Never, really. You just have to accommodate it and remember the hammer and grip are shaped differently than a Colt, Remington, or Ruger. You might try gripping it lightly and allowing the grip to rotated slightly in your hand in recoil, which should bring the hammer spur closer to your thumb. Cock the hammer while the revolver is pointing up. But then you will have to regrip for the next shot.
While we are at it, here is a photo of a S&W New Model Number Three. Notice the grip shape is quite different than the Schofield, but the hammer is still a reach when cocking it one handed.
And here is a Russian model. Talk about awkward, this one takes the cake. The Russians wanted that sharp, pointy 'knuckle' on the grip to prevent the revolver from rotating in recoil. It does an excellent job of that, but I find I have to completely regrip, placing the palm of my hand on the pointy part in order to reach the hammer. Then I have to regrip to get my hand below the pointy part again. If I forget, and fire with my palm in contact with the pointy part, it hurts, even with a relatively mild cartridge such as the 44 Russian.