When his drive was announced, Stanaway admitted "my approach last year and my attitude, which often stemmed from my own frustration, was the wrong approach at times" and apologised "to the people and fans that supported me and believed in me".
Adderton believes "Richie and Tickford last year set both of themselves up for failure" and "unrealistic" expectations weighed heavily, but that the driver will learn from it.
"I can assure, it's a very different Richie Stanaway," Adderton told Supercars.com.
"The conversations I'm having with Richie now after what happened to him in 2018, it's a very different Richie Stanaway.
"The fact he apologised in the press release for the way he behaved last year and letting people down, this is very different Richie.
"What happened to him in 2018, in my opinion, is probably going to be the best character-building thing that you could have, as a racecar driver."
Stanaway's two PIRTEK Enduro Cups included a Sandown 500 win with Cameron Waters