I thought this ingenious invention might interest some folk on here:
The SunSaluter is a solar panel rotator designed for the developing world. Using only the power of gravity with a water clock, the SunSaluter enables a solar panel to passively follow the sun throughout the day, boosting energy output by 30% and producing four liters of clean drinking water.
Earth rotation is, by definition, about a single axis. Therefore you only need one to track it. You are neglecting the possibility of an array normal that isn’t perpendicular to the axis of rotation.