Ferguson called time on his managerial career in May after a trophy-laden 26 years in charge at Old Trafford that saw the Red Devils collect 38 trophies, including 13 Premier League titles.
The 71-year-old will stay on at boardroom level though Charlton, who acts as a club ambassador, is confident Ferguson will only seek to assist Moyes, who was his own personal choice to replace him, in the former Everton manager's debut season in charge.
|11/1||Man Utd are 11/1 with Bet365 to win the Champions League
"Like Alex, Moyes has a work ethic and maybe there’s something the Scots know that we don’t because he’s a very good manager.
"He’s going to be quite happy here, I’m sure. He’s very, very professional and I think he will be a big success at our club.
"[Ferguson] is coming onto the board and he’ll be welcomed. It won’t change the philosophy of the club. He’s really clever and astute and the board is well aware of his capabilities."
Despite many seeing Ferguson's retirement as a signal that United's monopoly at the top of English football could be under threat, Charlton insists the future remains bright at Old Trafford.
"I thought about that of course when Alex told me he wanted to retire," he admitted.
"But, you know, I’m very confident. A lot of managers and media people will be saying ‘thank God for that United are not going to be a threat anymore’ but that’s a major mistake they’re mistaking.
"The philosophy will not change. The future was always there to look forward to from Matt Busby to Alex Ferguson and there will be another one. Football at Old Trafford will remain the same."
Moyes has been questioned by some on perceived negative tactics during his 11 years in charge at Everton, though Charlton believes that the 50-year-old will not deviate from United's attacking nature on the pitch.
"The philosophy of Manchester United has always been ‘attack’. Never be boring, never be dull. You can’t do that without creating things and I’m sure that will continue," he continued.
"Ferguson had the same philosophy as Matt Busby with regard to the game and how it was played.
"I have always said that we wanted the next manager to be a genuine Manchester United man.
"In David Moyes, we have someone who understands the things that make this such a special club."