You need both guys who come in to lock down games, and guys who get you to that point in the first place. Max Scherzer can do almost what Hader can do, except in 220 innings rather than 80. He should stay in that role. Hader got better as a reliever, because he could get by using only his two good pitches, and because he could go all out for shorter bursts. Hader is exactly the type of pitcher who should be a reliever rather than persist as a starter, because they're simply better in that role. But the guys who actually can reliably perform to that insanely high level over 200+ innings should keep doing that. That type of talent is in short supply, and whoever you get to pitch those remaining 120 innings will do a worse job of it. Times through the order penalty is real, we all know (or should know) that, it's not exactly news. But when you have someone who performs the same the third time through the order as he does the second (Like Scherzer has for his career), then why would you cut his innings total in half? Having one guy like that means you don't have to use your 2-3 inning guys that day, and you can use them better on the 4 days where you don't have Scherzer. Max Scherzer isn't immune to this line of thinking, either, though. He has a .480 OPS against the first time through the order! The 2nd, and 3rd time through, it drops to .638 and .645. Still good, but we have 9 guys who are better the 1st time through than Scherzer's 2nd or 3rd! That shows how powerful this analytical approach can be. This is why I just don't get the criticism when a starter is pulled and people say "Why? He was cruising." Well, Buehler was cruising yesterday too. It's just math and odds. Your reliever the first time through is still more likely to be more effective than your starter on his 3rd trip through the order.