People seem to be under the impression that the replacement club should either come from the unibond play off loser or the 14th club, but there is no reason why the replacement should come from the unibond at all.
All three feeder leagues have provided their quota of teams for the new leagues, and a team in the rymans would have just as much right to join the conference sub divisions as Ashton or Burscough. Boundaries would then be redrawn.
You need to get away from the idea that conference north = unibond. There are several Dr Martens teams in this league for starters.
The alliance committees I believe have the right to invite a club to join the league should the full membership not be met. there's no guarantee they will do, and if they do that it will come from the unibond.