Not really. Most devs usually consider universal apps just so that they can merge as many things and hit as many audience. So even if you support iOS8 only, you get:
960x640 (4S)
1024x768 (iPad2/Mini)*
1136x640 (5/5C/5S)
2048x1536 (iPad3/4/Air/MiniRetina)*
750x1334 (4.7 6)
1242x2208 -> 1080x1920 (5.5 6+)
So technically 6.
Let's suppose you do ignore iPads for the sake of argument, just because of the scaling of the device and the resolution changes, your anchor points for your assets (which you may be doing if you're dealing with games) just blew up in the number of variations. with the 5, you can think of it as a widescreen feature, one of your axis is still held intact; now, you suddenly blow out two more variations, and many existing middleware/frameworks were never meant to deal with it without some retooling.
*Sidebar: The minis actually throws up an even more interesting problem. On paper, the Mini retina and the Air shares the same pixel density, but because of the size of the device, you may actually change the UI element so that it maintains a usable size in real life. Many games actually detect for mini iPads and target a different set of assets entirely, which can increase your variation to 8.
Nowhere close to the android fragmentation, but it's something that many small teams may not be prepared for.