Meanwhile, Pep Guardiola’s men have been the dominant force in England this term, already sealing the Carabao Cup and boasting a formidable 16-point advantage in the league that could make them the earliest Premier League title winners ever.
Despite City’s form, which has been all the more impressive given the style they have played, Keown believes that United’s classic vintage is better.
“Manchester City are on their way to being a dominant force but Manchester United’s 1999 treble-winners would beat them,” Keown argued to the Daily Mail.
“I was part of the Arsenal side who finished a point behind United that year. That Gunners team was one of the best I played in, but United beat us in an FA Cup semi-final replay despite being reduced to 10 men, thanks to a moment of magic from Ryan Giggs.
“United always had one player who would do something special to dig out unexpected results.
"Where United were so strong was with four strikers all competing to be top dog. Andy Cole and Dwight Yorke would run the legs off you, then Teddy Sheringham and Ole Gunnar Solskjaer would come off the bench with a point to prove. And their finest hour in the Champions League final was delivered by those two substitutes.
"Peter Schmeichel was one of the Premier League’s finest keepers. He was such a daunting figure for strikers. The years he spent at the top should be a blueprint for Ederson at Manchester City."
Keown would not, however, discount the possibility of Guardiola’s side going on to dominate for years to come but feels they would lack the experience to trouble Ferguson’s men.
“City can be as dominant as the great Liverpool and United sides but winning trophies gives teams an extra layer of armour. That is what City would discover if they faced Sir Alex Ferguson’s treble winners today,” he argued.
City remain on course for a treble, although they were shockingly knocked out of the FA Cup by Wigan at the fifth-round stage.
Having thrashed Basel 4-0 in the first leg of their Champions League last 16 match, Guardiola's men are expected to cruise into the quarter-final following Wednesday's second leg at the Etihad Stadium.