"Hopefully that still goes ahead," Hamlin said.
"I just saw the position [advertised] – no great romantic story."
Hamlin applied and won the job after a Zoom interview with the selection panel, which included Walsh and Kurt McQuilkin - former NZ Heartland coach and current general manager of the King Country union.
Whanganui rugby has a good relationship with McQuilkin, who selected many locals in his New Zealand teams while maintaining the legendary Peter Rowe as his captain.
"He's got his finger on the pulse of it all," said Hamlin, who agreed the North/South Island dynamic between him and Walsh should help them cover the bases for finding the best players.
The coaching staff will have online meetings every Monday evening to compare their notes.
"We've got spotters [at games], and nominations have gone out to the teams."
Hamlin has experience at this level as, from 2014-16, he coached the NZ Marist team against Heartland in the annual McCrae Cup fixtures - a role Walsh took over in 2017.
He laughed that unlike the Heartland preparations, as Marist coach he would have to wait until two weeks before kickoff to start ringing around and find available players.
"With NZ Marist, we were on a shoestring [budget], and now we're on a shoestring but there is a lot of organisation involved.
"It's definitely interesting to see the other side of it."
For this one-off clash at Taupo's Owen Delany Park, Hamlin said the Barbarians lineup is likely to be fringe NPC players, youth and a strong base of Aucklanders, given the city is the Barbarian RFC home.
