After two more years in the 1st XV, he went straight into the Hawke's Bay Magpies after turning 18 in 2007, played Super Rugby for the Hurricanes the following season, and for the All Blacks in 2009.
"These boys aren't that far away," he said. "Three or four years and some of them could be professional sportsmen."
But it takes support from other quarters, and the team still needs financial support for the August 31-September 4 tournament in Dunedin, where Hawke's Bay will also be represented by Hastings BHS.
Guildford said schools must do more to recognise professional sport as a career option, alongside accountancy, law and other traditional pathways.
"Sports academies," he said. "That's the way to go. There are so many jobs becoming available in professional sports now."
His under-15 teams didn't have the biggest stars, he says, but won by having "the biggest heart".
An unusually large numbers of stars did emerge from those schooldays, headed by Guildford, who has now played over 180 first-class games. Among others were Super Rugby players Daniel Kirkpatrick and Richard Buckman and fellow Hawke's Bay Magpies Trent Boswell-Wakefield and Isaac Paewai.