Of guys who have had 1.2 Win Shares, we have 5 Spurs and 4 Heat:
Heat -- James, Bosh Wade, Allen
Spurs - Leonard, Parker, Duncan, Green, Ginobili
Sorting by total Win Shares, it is LeBron dragging along his slacker teammates and the 4 Spurs hauling the Ginobili anchor:
9th most Win Shares- Ginobili
8 - Allen
7 - Wade
6 - Bosh
5 - Green
4 - Duncan
3 - Parker
2 - Leonard
1 - James
James has 4.7 Win Shares. For the Heat to win tonight, he will need to register, in my opinion another 0.3 Win Shares tonight. That will give him 5. Only 3 players have ever had 5 playoff Win Shares in a season -- Duncan 2003 (win), James 2012 (win), Dirk 2006 (loss).
So James is having another great playoffs and dragging along the sorry asses of his teammates, so he is by default the Heat's Finals MVP.
For the Spurs?
Kawhi Leonard is at 3 Win Shares. Parker only has 2.5, so for Parker to pass Leonard he would need to go like 40 & 15 tonight and have Leonard go 0 for 22. That will not be happening, so Leonard will be the second most productive player in the entire playoffs.
His 3.0 Win Shares make Leonard the most overall productive 21 year old (or younger) in the playoffs ever. Ever. Soak that in a little.
PER - a stat that focuses more on offensive production and how much you possess the ball:
Again - James is well ahead of Parker and it will be impossible for Parker to even approach James no matter what happens tonight. The next three best offensive guys are Spurs.
Finally - Win Shares Per 48 - this stat would balance out the fact that LeBron is playing 42 minutes a game and all others are playing at least 15% less.
(this is why when you watch the two teams play you say "Wade and Ginobili look awful" - cuz it is true).
(you see now the reason why Green gets some Finals MVP promotion)
Now, James is WAY WAY ahead of Leonard and Leonard is WAY WAY ahead of Parker.
How good has Leonard been as a 21 year old? In 1980, Magic Johnson's total playoff Win Shares = 2.8 and WS/48 = .203. Leonard is at 3.0 and .200.
Folks - look at the names on this list: http://bkref.com/tiny/fXYGU. While several guys on the list were better offensively, for total Win Shares age 21 and under, Leonard is #1 and for WS/48 he is 5th (you could argue 4th since DuJuan Blair played 91 total minutes).
Conclusion - while these stats are not separated out by Finals/Non-Finals, if the Heat win, the Finals MVP should be LeBron; if the Spurs win, it should be Kawhi Leonard.