2) Best-case scenario: The starting pitching staff all have career average seasons
The Mets don’t need a Cy Young winner. What they need is for each of their starting pitchers to have an average year. Luis Severino going 14-9 with a 3.79 ERA would be welcomed even if he has managed to put together much better seasons with the New York Yankees in the past. Sean Manaea going 12-11 with a 4.10 ERA would be helpful, too, even if it falls well short of what the Mets starting staff actually needs.
Unlike many members of the bullpen whose career averages aren’t good enough, the Mets starters are better than passable if all they did was meet the mean. A pitcher like Jose Quintana has had such a long career that the range between his best and worst seasons varies so greatly thus so do his overall career numbers. His 3.57 ERA for the Mets last year was actually better than the 3.74 lifetime ERA in 12 MLB seasons.
Five pitchers with ERAs ranging as low as whatever Kodai Senga can do and up to the low 4.00s is going to result in a lot of success for the Mets. Adrian Houser and his 4.29 career ERA as a starter looks fantastic compared to what many other clubs have in their fifth starter spot. Don’t sleep on his 1.76 ERA as a reliever either.