I was wondering, How would you rank open-source OSs.

In order of most open source to least (left to right), would it be

AOSP > Sailfish > IOS ?

I guess what I'm saying is basic Android by itself is open source but it's what folks do to it that make it more closed, like adding google play services and such. Perhaps, AOSP + google play services would be put it more to the right of Sailfish. Would Mer be roughly the equivalent of AOSP in terms of openness? How would Maemo and Harmattan rank. Just asking

Feel free to add to pecking order of openness!