counting the iPad, apple has what? 6 hardware models that they keep supported at any one time? How many has samsung had in that time? HTC? Heck even nokia has had more than that. Now I am counting the 4 and 4S as different, when they weren't really.
Also Apple has had the ability to stand up to the carriers in the US. There are a few versions of the Samsung Galaxy S3 in the wild. I think it is at least 3.