What do you mean by ''Apple typically gives all of its iPhones unique names, but the company was said to be struggling with a naming scheme for this year's devices.'' ???
iPhone 3,3s,4,4s,5,5s,6,6s,7,8 , where is the unique name ? =D
The big one has always been called “plus,” for example. They haven’t sold two sizes with the same name before.