But in it's favour, the NPC in both SA and NZ would be back on centre stage and act as the premier competition within each country, instead of fans having a conflict of loyalty between Super Rugby and the CC/ITM Cup. And AUS would have a NPC to call it's very own.
SA and AUS could better capture their markets, and NZ could potentially reduce costs by supporting only 8 fully professional teams, rather than the 5 professional Super Rugby franchises plus the 14 professional/semi-proffessional provincial teams, it does now.
I see these two paragraphs as being the primary reason why this sort of idea would never fly.
NZ and SA destroying the history of their domestic competition by merging or disbanding teams is never going to align with the idea of making their domestic competitions take centre stage again.