Mono Wheel Method? | Space Engineers Experiment 

I can't believe it, Space Engineers got horses before Medieval Engineers. 🤣 So I think I understand why this dual gyroscope is behaving as such. with the setup you basically have a passive resisting gyro, and an active control gyro. with both at max, you're just canceling out their opposing forces, lower the override one and you have effectively made the active gyro that percentage stronger, and vise versa. I'm guessing at this part, but I would imagine that much like thruster overrides, gyro overrides on max power have a slightly lesser output than manual user input, thus explaining why you still have some gyro control while both gyros are at max power.

so you made a SE horse at the end? Might try to make it look more like a horse for fun.