I would keep the existing configuration, unless there are some sound arguments for modification. This is intermittent service, so efficiency really does not play a big role here.
The pump may require more head because it is likely to expect the the loading line to be above the maximum liquid level in the tank. So the additional head will basically be the difference between the maximum elevation point of the loading line and the maximum tank level. The result would be a proportional reduction in pump flow capacity - how much it depends on the pump curve shape. The new flow-head point would again have corresponding efficiency point on the pump curve.