Whether Manchester United will be able to bring in either of these two people with the money we don't know how much money the Red Devils have at the moment, however it will definitely take a long time to develop players, even if one of the top coaches is brought in by the Red Devils then there is a big possibility The Old Trafford public will wait the next two years so that the desired game can come true, but if it is far from expectations then of course it will be a waste of money.
It seems unlikely to happen following their (ancellotti and Pep) statements regarding their future at their current clubs (City and Madrid). Pep stated that he was unlikely to stay in the city after his contract expires soon and was keen to coach the national football club. Ancellotti has also emphasized how he is unlikely to leave Real Madrid until the end of his contract. It's impossible for United to recruit them. This sounds like a cheap rumor.
You can say it's impossible to happen today, but you never know what will happen in the future. I probably believe that Pep Guardiola would not accept a proposal from Manchester United even if it were in the future, it would obviously hurt everyone at Manchester City. Manchester United will likely bring in another top coach instead of Pep Guardiola or Ancelotti, so these rumors are still too far from reality even though they are possible.
Pep Guardiola and Ancelotti are both interested in coaching the national team. Ancelotti was rumored to be coaching Brazil, but I don't know what Pep Guardiola wants. Pep could coach England for the next few competitions if he really wants to usher in a new era for England, but I tend to take the stance that Pep will coach Spain.