Sir Jim Ratcliffe has outlined his plans to put Manchester United back on top of Europe, with a combination of glamorous football and hard-headed realism which he believes can knock Manchester City and Liverpool “off their perch” within three years.

Speaking less than 24 hours after taking control of football operations at Old Trafford, the 71-year-old billionaire admitted that United would have to learn stark lessons from the way their rivals had moved so far ahead in the 11-years since Sir Alex Ferguson’s departure.

Related: Sir Jim Ratcliffe says Manchester United culture not set up for success

In a wide-ranging interview, Ratcliffe refused to be directly drawn on the future of Erik ten Hag. However he said that failure of multiple managers since 2013 suggested the structure and atmosphere of the club needed fixing most of all.

“We have a lot to learn from our noisy neighbour and the other neighbour,” Ratcliffe said. “They are the enemy at the end of the day. There is nothing I would like better than to knock both of them off their perch.

“But they have been in a good place for a while and there are things we can learn from both of them. They have sensible organisations, great people within the organisations, a good, driven and elite environment that they work in. I am very respectful of them but they are still the enemy.”

United sit sixth in the Premier League, and have not won the Premier League since 2013, which clearly rankles with Ratcliffe. “It’s been a complete misery, really, in the last 11 years and it’s just frustrating if you’re a supporter. It’s one of the biggest clubs in the world. It should be playing the best football in the world and hasn’t been doing that for 10 or 11 years.”

But when asked for a time-frame for returning to the top, Ratcliffe suggested that about 2027 or 2028, when United will celebrate their 150-year anniversary, was realistic.

“The fans would run out of patience if it was a 10-year plan,” he said. “But it’s certainly a three-year plan to get there. To think that we’re going to be playing football as good as Manchester City played against Real Madrid last year by next season is not sensible. And if we give people false expectations, then they will get disappointed.

“So I think the key thing is our trajectory, so that people can see that we’re making progress. Because it’s not easy to turn Manchester United into the world’s best football team.”

Ratcliffe also revealed that the new regime would decide which style of football to play – with input from Ineos director of sport, Sir Dave Brailsford, and new CEO, Omar Berrara, brought in from Manchester City – with the manager then expected to fit that style. “We’re still debating what precisely is the style of football we want to play,” he said. “Look at Manchester City. All 11 [teams] play to the same formula and we need to do that.”

Ratcliffe said it would be “inappropriate” to discuss Ten Hag’s future. But he pointedly added: “If you look at the 11 years that have gone since David Gill and Sir Alex have stepped down, there have been a whole series of coaches, some of which were very good. And none of them were successful, or survived for very long.

“The only conclusion you can draw is that the environment in which they were working didn’t work. And Erik’s been in that environment. I’m talking about the organisation, the people in the structure, and the atmosphere in the club. So we have to do that bit.”

Ratcliffe also expressed his surprise that Newcastle had put a £20m price tag on their sporting director, Dan Ashworth, and suggested it was unreasonable to try to put him on gardening leave for 18 months.

“What I do think is completely absurd is suggesting a man who is really good at his job sits in his garden for one and a half years. We had a very grown up conversation with City about Omar. We sorted it out very amicably. And you look at Pep when he’s done with one of his footballers. He doesn’t want them to sit in the garden for one and a half years. He doesn’t do that. That’s not the way the UK works or the law works.”

In his first public comments since his purchase of a near 28% stake in the club was confirmed, Ratcliffe said he would look at the Mason Greenwood case and make a fresh decision in the coming weeks.

Asked whether it was feasible Greenwood could have a future at the club, Ratcliffe replied: “I don’t know. All I can do is talk about the principle of how we will approach decisions like that. Is he the right type of footballer, are we happy with the … is he a good person or not?

“It’s quite clear we have to make a decision. There is no decision that’s been made. The process will be: understand the facts not the hype and then try to come to a fair decision on the basis of values which is basically is he a good guy or not. Could he play sincerely for Manchester United – and would we be comfortable with it and would the fans be comfortable with it?”

Ratcliffe also confirmed that the club would be assessing whether to spend £1bn on upgrading Old Trafford’s decaying facilities – or asking the government to contribute towards building a new stadium, which would cost twice as much.

“In an ideal world I think it’s a no-brainer,” he said. “We would want a stadium in the north, a stadium of the north, which would be a world class stadium where England could play and you could have the FA Cup Final. But you have got to be practical about life.”