This comment is a stupid nitpick about the name of this error - I wouldn't bother bikeshedding about this, except that it's user-facing (we show the name of the error in the error message).

Should this be `GroupSizeBoundsError` or something (as I've said before, I'm terrible at naming - I come up with terrible names - doesn't mean I don't criticize names though - apologies for that.  :(  )

Because this is raised when deleting the server without replacing only, which violates budgetary constraints.  `ServersBelowMinError` to me implies that oops!  Somehow the number of servers *are* below the min, rather than "if we performed the request you suggested, they *would be* below the min".

Basically some name that clearly states "We can't do what you want, because if we did, such and such bad thing would happen"