Yep, and plus on the processor side, it doesn't have to render as much for x amount of seperate textures, there's only the aircraft itself. The Su-27/33 models themselves have six positions, so the processor has to render for each spot. While current processors are of course handling that, it just looks ugly when you look at the top screenshot. I don't know the reasoning behind the Mig, why it has it's insignia part of the texture, but overall given the complexity of the model itself (or that was why, the modeller just couldn't get the geometry right), I'm sure somewhere it's actually doing something staying part of the texture, rather than the seperate geometry.
Besides, there are people who are willing to waste the time to make other fictional skins, so it wouldn't be nothing but more choices ;)