The result marked Australia's first win in the Rugby Championship as the Wallabies overcame a sluggish opening 40 minutes to run in five second-half tries.

Cheika was pleased with his forwards who bounced back from set-piece troubles a week earlier to dominate the Pumas pack, but said he's considering tinkering with his back-row.

Wallabies skipper Michael Hooper has started alongside No.8 Sean McMahon and rookie blindside Ned Hannigan in all four Rugby Championship games, but Cheika said that could change on the spring tour.

"It's still a work in progress and we've got competition there, I thought [Jack] Dempsey was excellent when he came on and there's a couple of other chaps brewing in the background who we are looking to get a game in the back-row," Cheika said.

"Adam Korczyk is coming along very nicely and I would look at giving Lukhan Tui a run there at some stage, he's been practising a bit there... if he makes it on the tour we might have a look at that."

Hannigan has come under fire in recent weeks but Cheika defended the 22-year-old who bolted into the Wallabies side in June on the back of just 14 Super Rugby games.

"Ned has gone great, I want to make sure I say that, he wasn't even in the starting team for Super Rugby at the start of the year and he's played seven Tests in a row now," Cheika said.

"He's come from nowhere and I've really got a lot of respect for that guy because at first he had no idea what he was doing in the team, I don't think he even realised in June, seriously he was wondering why he was here.

"But he's stayed in the side and I know it's been a big effort for him but that's why I put him out again this week because I want him to get use to just keep going out there."

Hooper echoed his coach's comments and said it was a satisfying to let their rugby do the talking against Argentina, while praising his back-row teammates.

"The intent to improve there has been fantastic, Ned's want to get better each week has been fantastic and Seany has been terrific on the back of not much Super Rugby," Hooper said.

"I'm enjoying playing with the guys and enjoying what our team can put out when we start doing the stuff we talk about doing and that's what it comes down to."

McMahon said playing four straight Tests with the same back-row combination has helped the trio build consistency.

"It's been getting better as we get a bit of consistency playing with each other, Hoops is doing what he always does being a hyper bunny and it's then just up to me and Ned to add what we're doing," McMahon said.

"I get a little bit more freedom in trying to find a few more ball carries but I think it's been working well over the past couple of games and we've just got to keep working towards getting better every week."

Hannigan, Izach Rodda and Jordan Uelese all became Wallabies this season after starting the year as Super Rugby bench players and Cheika acknowledged there's a limit to how often he should use young players in the Test arena.

"I think that's a smart way of thinking, depending on the load and also the mental load, especially when you're coming from nowhere," Cheika said.

"I definitely consider those things when I go into each selection for the young players so we make sure we try to get them experienced and set them up for success."

The Wallabies next face the Springboks in a fortnight in Bloemfontein, before facing Argentina in Mendoza the following week.