Please post data sheets or other documentation of those motors.
PWM pins are not necessary for stepper motors. Their drivers take a digital pulse per step and the direction a digital level. PWM pins can be used to control the speed of a DC brushed motor, not a stepper.
Robin2's stepper motor basics tutorial.
Each stepper driver of the step/dir type takes 2 or 3 (optional enable) GPIO pins. If you are using motors like the 28BYJ with ULN2003 drivers, they take 4 pins, each.