The minimum torque for the speed stages is 1. In other words, if there is any torque at all, it runs, and if there is no torque, it doesn't run. However, due to the combination of minimum power and minimum speed requirements, the math gives you a torque greater than 1 if you meet the minimum requirements exactly. You are however free to use more than the minimum speed. Rotarycraft machines operate faster the higher the input speed is.
Example: the extractor stage 2 requires 2048 rad/s and 16384 W power. Mathematically, that requires you to apply 8 Nm of torque (2048 * 8 = 16384). The operation time at that speed is 180 ticks (9 seconds). However, those 8 Nm are not a requirement, you only need 1 Nm. You can for example throw another 8:1 gearbox in there and drive that stage with 16834 rad/s, 1 Nm instead. That still satisfies the minimum power and speed requirements both, but now the operation time dropped to 120 ticks (6 seconds) because of the increase in speed over the minimum value by three (binary) orders of magnitude.
Admittedly, looking at the Rotarycraft community wiki, the information there could be presented with more precision. I'll have a look whether I can tweak it to be more clear. (EDIT: Tweak applied.)