Looking at team numbers: Coastal, Bays, Tech, Halswell, FC, Nomads, Waimak, Selwyn/Rolleston. Thats plenty of options (all of the above have 50+ teams according to mainland) Throw in Western, the Uni Crew for seniors, Pap Redwood (who could really only merge with western or nomads due to geography), a burwood/parklands merge would give a big club, united (if they survive) as well as mid canty, amberley etc who cater for those outside the metro boundaries.
We have enough options. How clubs like St Albans with 9 teams in the whole club survive are beyond me.
When it gets to a north, south, east and west situation at club level then the concern is justified