The Highlanders announced on Tuesday that Joseph, who previously coached the Highlanders from 2011 to 2016 before returning this year in a head-of-rugby role, was to return as head coach.
It means incumbent Clarke Dermody is nudged down to forwards coach.
Kean felt the Highlanders were fortunate to recruit Joseph in the new head-of-rugby role after he completed his stint with Japan after the World Cup but it became apparent there was a better use of the coach’s talents.
"You sit back and you go, well, how do we get the best out of the coaching crew that we’ve got?" Kean told the Otago Daily Times.
"We looked at it and felt we had unique skillsets, both Jamie and Clarke, and we’re probably not utilising Jamie’s to the fullest.
"We want to look to the future. We want to make the most out of these guys while we’ve got them here.
"It was sort of counter-intuitive not to make this change because we just didn’t feel we were getting the best out of Jamie as head of rugby."
Dermody has spent a full decade with the Highlanders in off-field roles and has just completed his second season as head coach.
While he had a year to run on his contract, he was fully on board with the move to bring Joseph back in the top role, Kean maintained.
"Clarke’s very fired up about it. He’s pleased to be part of the setup, and he really is a key part for us.
"We really wanted Clarke to stay and he never suggested anything other than he was in, boots and all.
"He’s a Highlander man. He and Jamie have worked together before, they get on well, and they’ve been successful. It was just a matter of talking it through with those guys.
"I think it’s quite exciting that we’re going to get the best out of both guys."
The Highlanders head-of-rugby role would be discontinued, Kean said.
Joseph would effectively have complete control of rugby operations, including recruitment, and would be working with Dermody to finalise the rest of the coaching staff.
Kean, who has known Joseph a long time, feels the Highlanders are blessed to have the master coach back, and he is excited to see what he can do for a club that has battled in recent seasons.
"He is very structured in his thinking. And he does think way ahead.
"You talk to him and you understand how the role has evolved. You’re almost a CEO of rugby. You can’t just be thinking about the 23 you’re picking for one week.
"It’s about how the season is going to play out, how the following season will play out, how your recruitment is gong to work, how you’re going to get the best out of your management and coaching team, and how you are going to put worthy business plans to the board.
"He’s a complete rugby person now because he’s done it all."
Joseph was signed on a four-year deal when he returned to the club.
Contracts tend to be flexible — witness Kenny Lynn leaving the Highlanders after just a year as attack coach to join Argentina — but the club will be eager to see Joseph in place for as long as possible.
"I think we’ve been lucky to have him for a year but I hope like hell we get the other three years out of him," Kean said.
"Coaches are plums when they’re as good as him. We’ve got to try to keep him motivated to stay with the Highlanders."
Kean felt the Highlanders made some progress this year but noted they were still struggling to beat the best teams in the competition.
Loyal sponsors and boosted crowds were appreciated as they were now planning "quite a big capital expenditure" to upgrade their facilities next to the stadium.
