Win Shares Leaders In the Playoffs 1990-99:
Jordan, Jordan, Jordan, Barkley, Hakeem, Shaq, Jordan, Jordan, Jordan, Duncan. (Jordan most productive 6X, assorted others 1 each).
Win Shares Leaders In Playoffs 2005-2014:
Billups, Nowitzki, James, Garnett, James, Gasol, James, James, James, James. (James 6X, assorted others 1 each).
Now, the 2014 playoffs are not over, so if the Pacers win then either Paul George or Kevin Durant (or both) may pass James. But that is the only realistic non-LeBron scenario. George is a full Win Share behind. Durant 1.1, Duncan and Splitter are next at 1.3 win shares behind and it has taken both men 15 games to reach 2 WS, it isn't real likely that they will put up say 1.6 more WS over the next 11 games. So James would have to lose, play not very well while losing, and then Durant and/or George would have to go on a tear and play a lot of games.