Yes, you need to Y the plugs together, I built a separate switch box for the Stokers and Combustion Blowers, so I can control each separately. But still have them plugged into the CoalTrol.
The stokers/burn may vary a bit from side to side, it just depends on the stokers. Not sure if the factory ones with CoalTrol have any adjustments on the feeder?
Mine had the old Adjustment knobs and i can fine tune the feed to match both sides.
Check the back of the Stoker Plate, might be a screw at the end to adjust, but with the CoalTrol factory, they may have removed it? both should be adjusted to MAX (IN) and let the coal trol maintain the MIN/MAX of the fire.
Min/Max won't affect the stokers if they are out of adjustment. Mine are a little off, maybe 1/2"-1", once burns back a bit farther then the other, but I don't worry about it.