Ah, those pictures are exactly the same resolution as they are in the games. They appear smaller because the screen resolution is higher not the image resolution. Similarly, a larger picture does not necessarily coincide with lower resolution.
 
What you said was that the screen shots are in a higher resolution. As I said, it's not the screen shots, it's the screen itself.

A simple mistake, though, I'm happy to drop it. :)
 
That would have been an interesting challenge - link the two games so WCIV would recognize who died in III. WCIV assumes the winning path in WCIII with Maniac happily alive.