An assembly and techniques for employing multiple motors to drive an oilfield injector. The injector is configured to drive a well access line such as coiled tubing and the motors may be electric in nature. Additionally, the motors are configured to operate at substantially sufficient cooling speeds for electric motors. Nevertheless, the motors are coupled through a common differential mechanism such that a range of differential speeds may be derived via comparison of the operating speeds of the motors. Thus, a wide array of injection speeds may be employed without requiring the motors to operate at dangerously low speeds in terms of electric motor cooling.