The problem with someone like Kallis in an all-time line-up is that he is not getting into the team on his batting alone (well, very unlikely) and his bowling - like Sobers - is someway off the requisite standard for these kinds of match-ups.
Every player has to bat, but not every player has to bowl. Imran on his bowling alone gets in, and he is one of the best batsmen in terms of bowling all-rounders.
The same, maybe even more, goes for Miller. I don't really know about Proctor's bowling but was he the best in the world at any stage? Because for a time Miller arguably was - or was as good as Lindwall was.