DC motor speed reduction
If the motor has no internal electronic commutator and you have successfully operated the motor by direct correction to a battery, you have confirmed that the motor is some type of commutator motor, not a motor that required a controller for brushless motors.
Any electronic speed controller (ESC) that works by reducing the voltage applied to the motor should work reasonably well. The specifics of the motor design, number of poles etc. will not interfere.
Simply reducing the motor speed has the disadvantage that the speed will vary somewhat due to the internal voltage drop in the motor resistance as the current varies due to load variations.
If you were to insert a variable series resistor to control the speed, that effect is more severe. Also the power dissipation in the resistor can be problematic.