Australia coach Joe Schmidt has picked his fourth captain in six Tests by naming number 8 Harry Wilson to lead the Wallabies in the Rugby Championship clash against Argentina in La Plata on Saturday.Wilson follows Queensland Reds team-mate Liam Wright and props James Slipper and Allan Alaalatoa, who have all captained the side in Schmidt's first season in charge."Harry's been really good for us, and I think he's led himself really well," Schmidt, who led Ireland between 2013 and 2019, said."He has a natural propensity to express himself well, but with very few words."I don't think that we want to be doing too much talking."It's about the actions that he's going to deliver and lead from the front, effectively."Following crushing, back-to-back defeats on home soil against the world champion South Africans, the Wallabies' hopes of winning the Rugby Championship are on a knife-edge.Schmidt has made five changes to the starting side that slumped to a 30-12 defeat to the Springboks in driving rain in Perth.Tighthead Alaalatoa drops to the bench after captaining the side against the Springboks, making way for Taniela Tupou who returns to the matchday squad named on Thursday after mourning the death of his father.Hooker Matt Faessler will start alongside Tupou, replacing Josh Nasser in a revamped front row.Hamish Stewart will make his Test debut at inside centre, replacing injured Reds team-mate Hunter Paisami, while scrum-half Jake Gordon and lock Nick Frost return from concussion to be included in the starting 15.Schmidt has given Noah Lolesio another chance to cement the starting fly-half position despite the ACT Brumbies' number 10 struggling behind a beaten forward pack against South Africa.Western Force out-half Ben