But they aren't the only schemes with scale issues. All the union-based KiwiSaver schemes, for instance, are struggling to attract members. Another profession-linked scheme, the Law Retirement KiwiSaver, reports just over 400 members.
The Macquarie Bank-owned Brook Asset Management is also something of a mystery presence in the KiwiSaver space. Brook was a big name in NZ funds management before its two principals, Simon Botherway and Paul Glass, abandoned ship in 2008. Since then Brook's funds under management, especially in the wholesale world, has evaporated.
Last week Brook shut down its Tasman Wholesale fund, which at one time was a huge component of the $1 billion plus the company managed.
Mark Ryland, appointed as Brook managing director last November, says the firm is concentrating more in the retail investment arena these days.
Ryland says Brook will continue to run a retail version of the Tasman fund, which currently has about $20 million under management.
He admits the Brook KiwiSaver scheme, which has approximately 400 members and $6 million under management, hasn't met expectations.
"[The KiwiSaver scheme] didn't really have a distribution strategy," Ryland says, but Brook and its Australian owner haven't given up on it.
The group recently restructured the scheme, adding a conservative option to broaden its appeal.
Ryland says Brook is also aiming to partner with corporates and independent financial advisers (as well as the Macquarie Private Wealth network) to push the KiwiSaver scheme.
It will, however, be an upstream battle.