Haha now we are talking. Things look quite a bit different when you don't use full career. Kudos to you for going to find all that. Makes me want to vote on you just for the effort. ( Being serious not sarcastic).
As you can see, at minimum now we are looking at a nice matchup, not some blowout lol.
The point I will argue on WAR. The stat isn't foolproof.
Closer- You state your team has a big metrical advantage and according to WAR yes. But realistically it just doesn't make sense.
Lee Smith 1983 the year you used for him- ERA- 1.65 SAVES- 29 LOSSES- 10
Eric Gagne - 2003 ERA- 1.2. SAVES 55 BLOWN SAVES 0. Cy Young Award Winner
The guy was perfect, literally the undisputed best season ever for a closer and your WAR argument suggests that Smith was better. He lost 10 games that year with just 29 saves.
I can go through player by player and find discrepancies on the WAR like this, but just wanted to highlight the first that caught my eye. It is not possible to have a closer advantage on a guy who went 55/55 with a 1.2 ERA.
Touche for all these stats you are gathering, but WAR is just not a perfect metric by any means and also takes a team's record into account. Nolan Ryan by any publication is one of the best pitchers ever, and is the MLB strikeout leader. His 7.8 WAR is simply not indicative of his real value to his team, because the team around him stunk. If your team doesn't win a lot of games, your WAR won't be good. Throw him on the same teams Seaver was on, and it's likely Ryan's WAR is higher.
Ryan had one season with a 1.69 ERA- absurd for a starting pitcher, and in that season his WAR was just 4.7 because the Rangers were bad.
Seaver on the flip side had an ERA of 1.76 in his best season, while his WAR was above 10. Why would you ever value a higher ERA?
Let's not understate Nolan Ryan's greatness. He had 5,714 strikeouts in his career. Your Seaver was actually 6th best ever in that regard and had just 3,640.
Lower ERA and more strikeouts, I know which one I'm taking...