First: "I do not need to run any of these at the same time, and they will only go one direction"
So instead of using 4 DC brush motor controllers for each motor I thought I could simply use one, then run the output to 4 N-channel mosfets, a mosfet for every motor. Then use 4 arduino pins to turn which motor I want on, then control the motor controller like normal. But then after reading how this motor controller works I realized that I can just simply use 4 mosfets, connect each mosfet Gate to an arduino PWM pin, and those would be my 4 independent motor controllers.
Is it that easy? or I missing something?