North’s back six for round one is still far from decided, and it seems everyone has an opinion on how the Roos should structure up.

While Scott Thompson, Michael Firrito, Joel Tippett and Robbie Tarrant have all enjoyed significant game time during the NAB Challenge, Lachlan Hansen is still touch and go for the season-opener.

The fact remains though - it’s unlikely five talls will be named in North’s 22 against the Crows.

So who gets the nod?

Fox Footy commentator Cameron Mooney weighed into the debate on Tuesday night.

“My biggest concern is their back half,” Mooney said.

“I look at their numbers last year in the finals. We talk about Thompson who is a star, Firrito who has been a great player, but you put them on the big guys and they get goals kicked on them.

“You look at their finals last year; Essendon, (Joe) Daniher kicked four goals, (Tom) Hawkins just about snatched the game away from them in the semi-final, he kicks five. Then you go to a Preliminary Final – their big guys (Lance Franklin and Kurt Tippett) up there kicked nine between them.”

Mooney said North needs more strength down back, with forward-turned-defender Tarrant the most likely type.

“I want Robbie Tarrant down back, I think he’d be really good down there,” he said.

“We’ve seen his brother (Chris) do it at Fremantle and Collingwood.”

The former Cat also keen to see Tippett given an opportunity.

“They’re both (Tippett and Tarrant) inexperienced down there. I’m not saying let’s throw them down there and it’s going to work, they might get absolutely belted from pillar to post in the first couple of rounds.

“I think they need to try it because Thompson and Firrito get beat up by the big boys. “

While much of the discussion is around the talls, North’s running defenders will be vital to its success in 2015.

“I get a bit concerned about the Kangaroos’ decision-making and accuracy coming out of defence,” Gerard Healy said.

“(Luke) McDonald is a good young kid, but I think he’s got to get better with his feet.

“(Sam) Wright, (Shaun) Atley and (Jamie) Macmillan; I think all are a bit prone to being a bit nervous with their skill execution. If that’s something they can improve on, it’s going to set them up well.”

Both Healy and David King identified Atley as a potential improver.

“Atley’s stats tell you he’s an inside-mid as a kid. As an AFL player he’s a running half-back who I think doesn’t do enough with the football,” Healy said.

“He’s still got this other gear or two to go up, and if these gears all click in at the same time, look out Kangaroos.”

King in particular excited by the number 18’s prospects.

“He’s top 30 in the competition for groundball gets in the back 50. He understands how to get his hands on the ball,” he said.

“He still doesn’t have the confidence, which is remarkable, to put it to other teams. He does it at training, he embarrasses his fellow teammates, but he doesn’t do it in games.

“When that penny drops, which I think isn’t too far away, he’ll become a goal-kicker, become a line-breaker for them pretty quickly.”