Those motors themselves should be OK. But I would guess the information about one pin high, one pin low was actually talking about driving the motors via a motor driver like the old L298N or perhaps a more modern version.
You will need something similar because the Arduino pins definitely cannot provide enough current to directly drive any motors without damaging the Arduino.
Make sure that both the servos and the motor/motor driver are powered directly from whatever battery or power supply you will use. The Arduino only sends control signals to them NOT the main power.
Steve