Well, the debate here gets murky because playoff baseball is not managed the same as regular season baseball. There’s strategy deployed at all times. In this case, it’s simply putting who you think is a better pitcher in for the 6th.
I was talking more of regular season games. Meaning in the 6th inning, if Cavan Biggio comes up and there’s a lefty (or actually anyone if you’re a good team) pitching, you’re probably subbing him for someone that’s giving you a better chance to score. If Kirk gets a base hit, are you running off him in the 6th? Prob not. So get Tapia or Zimmer off the bench.
Can a game in the playoffs or even regular season be decided in the 3rd inning? Of course. Not all 7-9 innings will matter. So in that case, sure, each inning is important in its own right and comes with its own set of pressures. Unfortunately all of your arms aren’t the same and so you have to pick who you want to keep for the high leverage situations