The online publication believes that Apple's sweet spot is the 4.7-inch iPhone model. The 5.5-inch is for folks who would like a larger screen and the iPhone SE is perfect for those who like using a smaller phone.
AppleInsider thinks that if a third iPhone model were to emerge, it would be an upgrade to the current iPhone SE line. This way customers would be able to choose between 4-inch, 4.7-inch and 5.5-inch iPhone models.