The servo has the benefit of creating a smooth polynomial function which in this case also sets the upper and lower deflection range which are not symmetrical.
When you replace this with an actuator with a range of -1.0 to 1.0 then the servo no longer deflects the elevator by 30ish degrees but at an insane 57°. I would recommend using a polynomial object after the actuator with the same coefficients as the servoclassic.
As far as I know the actuators in the CRJ are hydraulic and not electric. So not sure why you would want to use electric actuators here.