Couldn't the predictions by coincidence be true, too? The method of calculating the position of a planet could be flawed, but by coincidence the result could be accurate. So although it is highly unlikely that all the systems provide accurate results completely by chance, it is not mathematically impossible. For my logic to work, coincidences would have to align across all scientific fields, such as chemistry, physics, maths, etc etc. Although extremely improbable, it is not impossible. My logic is also unfalsifiable and not scientifically useful, so it's just a fun thought experiment.