Stepper motor with driver A4988

Torque and number of degree stepper are not related. You.can buy 200 step motor that will have different torques

For a given voltage, torque and speed in a DC motor are said to be inversely proportional. The speed-torque curve that you see on data sheets is only valid for the rated voltage and the motor will operate on that curve. So if torque goes up, the speed will follow that curve and go down.