After checking data at Baseball Reference, 1974 looks like the first year that none of the top 3 vote getters in either league were among the top 10 in WAR. I did not find this happening in any year before, even if in only one league (if I missed one, let me know). At least one of the top 3 vote getters was in the top 10 of position players or pitchers in all previous years.
Here are the top 3 in each league from that year:
Mike Marshall (not in the top 10 for pitchers)
Now this is not a systematic analysis. Maybe other years were worse in terms of how well WAR was correlated with the points each guy got.
There were 3 times I found where the winner was not in the top 10 in WAR, but at least one of the other top 3 guys was
Powell 1970 (Oliva was 2nd in voting and was in the top 10 in WAR but Killebrew (3rd) was not)
There were some cases of a winner tying for 10th (Boyer, Campanella). Konstanty was 7th among pitchers in 1950, but not in the overall top 10 (which combined pitchers and position players).
Now Frisch and Cochane were also managers. Maybe that influenced the voters.
In 1974, Reggie Jackson, Gene Tenace and Bert Campaneris all had more WAR than teammates Rudi & Bando.
In the NL, Garvey led his team in RBIs and batted over .300. His teammate, Jimmy Wynn, beat him in WAR, 7.6 to 4.3. But Garvey beat him in AVG (.312-.271) and RBIs (111-108).
Brock set the then SB record with 118. Maury Wills won the award in 1962 when he set a record with 104, so I guess the voters thought Brock had to get some consideration. But Garvey's Dodgers won their division while Brock's Cardinals did not.
Mike Marshall set a record for games pitched with 106 and won the Cy Young award while pitching for the Dodgers.
Jeff Burroughs led the AL in RBIs with 118 (while also batting .301). But his Rangers did not win their division. Only one other player, Bando, had 100+ RBIs in the AL (he had 103).
Here is something I found about that year's MVP vote from the following site
"Lou Brock, who finished second to Steve Garvey in the National League MVP voting, says he wouldn't accept the MVP next year if he stole a thousand bases. Brock, who had his best year ever, expected to get the award and even set-up a press conference. Brock beat Maury Wills' 12-year old record of 104 steals."I found a NY Times article through my school's library that confirms the 1000 base quote and this is how I recall it. Brock also said the voters used "bad judgement" and his manager, Schoendienst, agreed.
Click here to see the MVP voting for both leagues in 1974
Click here to see the WAR leaders among position players in the NL in 1974
Click here to see the WAR leaders among position pitchers in the NL in 1974
Click here to see the WAR leaders among position players in the AL in 1974
Click here to see the WAR leaders among position pitchers in the AL in 1974