Will 10 ounces of juice ferment the same rate as a gallon of juice, with the same amount of yeast and sugar added in both?
Quick answer No.
Longer answer no not exactly, you may or may not notice the difference if you took a gravity reading every 30 min, but if you just take 1 reading per day you are unlikely to notice.
If you were to add the same proportion of yeast to the same volume then yes, in gallon vs 10oz volumes then you would see no difference. If you add the same cell count of yeast per unit volume then you tend to get the same rate of fermentation regardless of the total volume.