The stall current gives a guideline for the maximum current draw you can expect from each servo so you can budget how much current you need to be able to source from the regulator and power supply. I cannot say if 1A per servo is sufficient for your servos; some servos can draw many times that, but from the torque specifications of those servos, I suspect they draw more than a standard servo (which we normally suggest budgeting an amp each for).
If you have a bench-top power supply, you might try connecting a few servos and moving them around and see if you get a voltage drop from the load of the servos(a sign that they are drawing more than the power supply can handle). If that seems okay, you could add additional servos one at a time again moving them and seeing if you get a voltage drop. If you do not get a voltage drop, the maximum current for your bench-top supply will give you some idea what current you need. You can also try adjusting the maximum current on your supply down until you get a voltage drop to further narrow that range.