I think it's important to be clear that a song is so much more than just the chords. Axis uses a few "tricks" to get things to sound the same:

- strip away everything except the chords & play them all on the same instrument - shift all the songs into the same key - play all the songs at the same tempo

It's a funny exercise that, but it's a bit like saying all cars are the same because they have the same basic structure. Obviously there's a difference between a Camry and a Bugatti.