You can put this is the correct location if you feel it necessary to move it.
I have 2 Mad Catz mice that has index clicking issues. One I just bought and the other is several years old.
Mad Catz MMO7+ wireless gaming mouse - recently new purchase. The index button on it sometimes double click in a weird fashion. If I hold it down upon releasing the button it makes a second click. I might be able to return it, in which case that will be my solution to the problem. But not sure why it clicks more than it should.
Mad Catz RAT 8+ wired gaming mouse - older mouse. The index button on it when I click on occasion it double clicks as if I made 2 clicks when I just pushed it once.
I love the Mad Catz layout and functionality of their mice especially being able to customize LEDs and change attachments.