That still may not fix it at all. Ideally the overflow needs to be on the lowest reservoir. All the water wants to go downhill. If you get that overflow in the top tank too low you will be pumping your sump dry because all of the water will eventually go out your overflow. In this case eventually may be minutes or seconds. I cannot see any way to make a drip system work in an open sump unless the overflow is in the sump.
The tank depth is regulated by the drain pipe to the sump. The sump depth is regulated by how much water is in the tank. Add water, sump gets fuller, not the tank. Remove some water, sump gets shallower. Add one drop to the tank, the sump gets one drop deeper. The overflow needs to be in the sump in my mind.