And 27-year-old Ameliaranne Ekenasio has likewise performed strongly with an 83 per cent success rate at the hoop.
"We've stepped up in the shooting this year and I know all of them are working really hard to make sure they take their opponents to task," Southby said.
Selby-Rickit, 24, nailed 81 per cent of her shots in Launceston, including five from seven in the final quarter.
Yet despite her strong form, she had been given no guarantees of a starting berth in Saturday's tussle in Auckland.
"We've got some great shooters in the team so it's good to know we can always change it up, and everyone brings something different," Selby-Rickit said.
"I'm just trying to stay composed."
The Invercargill-based Selby-Rickit said Tutaia had been a great help during her injury lay-off, providing plenty of tips and tricks to deploy on court.
Her ability to net from every inch of the circle could be key, if called upon, in securing a second win of the series.
"She's played 102 caps, she's got so much experience against Australia," Selby- Rickit said.
"I'm not expecting a start but any opportunity I get on court, I'll take it with two hands."
At the other end of the court, the Silver Ferns have their own shooting champion to tame in Diamonds finisher Caitlin Bassett.
The 193cm Bassett ran riot in the first Constellation Cup tie in Sydney, scoring all 47 of her shots on goal, and nailed 40 from 43 in Launceston.
Centre Shannon Francois admitted there was little any netball side could do to stop Bassett when under the posts.
Instead, the 28-year-old Diamond had to be starved of possession.
"Our job is just to promote ball for the goal keeper to come out and get, or to stop it from getting anywhere near that shooting circle," Francois said.
"The Diamonds are going to come out with a whole new intensity so we need to be prepared for that and absorb it."
Each side has won one Constellation Cup tie with two games on Kiwi soil remaining.
