Let’s compare two different forehands.
Fish hits WW FH and Djokovic strikes Hard TS FH. Both employ pronation and wrist ulnar deviation. Image #3 shows that Fish racquet is vertical and parallel to his chest, that’s why this type of FH is called WW FH, but Djokovic racquet is closed (corresponding image #3) and perpendicular to his chest. Djokovic FH has absolutely nothing to do with WW FH. This is one of the ways to play winners.
What causes so big difference in follow through? The answer is that Fish applies passive wrist actions, but Djokovic uses actively wrist ulnar deviation
. The same does Hantuchova, post 37, and this explains why the skinny super model still is very successful in WTA.