"Tom had a bit of a mixed bag [last week], so we thought he'd have a go this weekend," said co-coach Jason Hamlin.
"Angus is in the same boat. We'd like to give everybody in the first four games a start.
"Kaveni [Dabenaise] and Samu [Kubunavanua] aren't even in the team. I was telling players it's not that they're doing anything wrong, we've got a pretty big squad and giving everybody a go."
History favours the teenaged Hemi as in the previous two seasons the Poverty Bay game represented the 'coming of age' moment for the youngest Wanganui squad member.
Future Blues first-five Stephen Perofeta scored a hat trick at Cooks Gardens in 2015, while last year Te Rangaitra Waitokia got four tries up in Gisborne on his way to being named Heartland Player of the Year and getting a Manawatu Turbos contract.
After three months stewing on the sidelines while his groin strain recovered, Hart got through 50 minutes for the Wanganui Toyota Development XV last Saturday and was not keen on being subbed.
"We're pretty happy about that. Fraser [Hammond]'s out and Sokonaia [Kalou's] in a bit of doubt because of his knee," said Hamlin.
Again, Baldwin and Tutauha remain interchangeable both for the rake work and guiding their squad mates.
"They're two quality footballers and they're sort of developing as leaders, we don't lose anything," said Hamlin.
After making last year's Lochore Cup semifinals, Poverty Bay have not had a good start with comphrensive losses to Mid Canterbury (34-5) and Horowhenua Kapiti (39-5), with coach Mana Otai being steadfast in his belief about not adding more loan players.
Only the returning Isaia Vuki, from the Bay of Plenty, is an outsider and comes into second-five this week after scoring his team's sole try from the bench last Saturday.
"They look like they got enough with the locals," said Hamlin.
"There look to be a few spaces we can attack through. We thought the same against Thames Valley, but we didn't get the ball.
"We get some good possession - sooner or later we'll break teams down."
After Thames Valley gave the side a real fright last weekend at a soaked Paeroa, that result and the swapping out of several regular starters has seen a much more serious approach this week.
"We're trying to keep them fairly grounded," said Hamlin.
"We talk to them till we're blue in the face but if they don't take the lessons on board, we won't get the results."
There are 12 Wanganui survivors from the side that made the trip to Gisborne last year, as along with Waitokia, Horrocks and Hart were tryscorers that day.
Kickoff is 2.30pm.
The teams are
Wanganui
1. Hamish Mellow; 2. Cole Baldwin (c); 3. Viki Tofa; 4. Sam Madams; 5. Campbell Hart; 6. Tremaine Gilbert; 7. Angus Middleton; 8. Bryn Hudson; 9. Tom Stewart; 10. Craig Clare; 11. Bruno Tuivai; 12. Timoci Seruwalu; 13. Jona Sawailau/Kaveni Dabenaise; 14. Simon Dibben; 15. Cody Hemi.
Reserves - Forwards: 16. Roman Tutauha; 17. Gabriel Hakaraia; 18. Sokonaia Kalou; 19. Jamie Hughes. Backs: 20. Lindsay Horrocks; 21. Dane Whale; 22. Cameron Crowley.
Poverty Bay
1. Tamanui Hill; 2. Matekairoa McGuire; 3. Sione Ngatu; 4. Leslie Hills; 5. Everard Reid; 6. William Tamatea; 7. Fawn White; 8. James Grogan; 9. Willy Grogan; 10. Kelvin Smith; 11. George Halley; 12. Isaia Vuki; 13. Jesse Fleming; 14. Karl MacPherson; 15. Ethine Reeves.
Reserves: 16. Sandy Hohipa-Campbell; 17. Semisi Akana; 18. Jacob Cook; 19. Mekepio Brown; 20. Mario Counsell; 21. Tawhao Stewart; 22. Anthony Karauria.