Yeah but those are two different things. Kimbrel feels like long overdue payback after Robertson (the first time), Hunter, Neshek (the second time), Knebel, Kintzler, Familia etc. (Brad Hand was okay but just okay. Ditto Archie Bradley).
Kerkering, OTOH, could be the next Neris or Seranthony, which is a whole other level of value until they reach their last couple of arb years (and even then they are still good value if they don't crater/break). So I understand why some would keep him especially after losing Brown. But he's still not as valuable as the three starters (even if one of them might still end up a reliever himself).