There are actually two versions of WAR that are commonly used.
One is Baseballreference.com and the other is from Fangraphics.
They are similar but not identical.
This sheds some light on the WARs
https://www.samford.edu/sports-analy...ll%2DReference.
Bill James also has a different
Uber Stat that he devised called "Win Shares"
Win Shares measures a player's total contributions across positions, teams, and eras. The general approach to calculating win shares is to divide a team's win shares between offense and defense.