No thanks. With this approach you'd be artificially limiting availability and leverage, IMO. Like what if you only need 3 of the group B to finish a given game, you then won't use any of them the next day because you wanna stay with this pairing? If no, and you'd use guys if needed, then you don't actually have a pairing.
I would t make any changes to overall usage. Cano to Bautista unless he's unavailable. Those are the only guys I really trust right now, so bridge to them however needed.
Agree that when Tate and Givens are ready, Voth and Irvin are the guys to go right now. I wouldn't yank Grayson from the rotation yet, and probably not even if he has another dumpster fire start. I'll ride that out a while.
Wouldn't be hard and fast, just a general intent. If you need others, it's not like they aren't there and available.
But generally would help imo. Guys would know when they could be expected to be used (which they like), and would keep everyone fresh.
Buck more or less did this, and worked well.