Point 5 is bollocks.
Real's "Galactico" strategy is nothing to do with weakening the competition in their own league. At all. It's entirely about creating an ethos and mystique, driven by marketing and brand values, of buying the biggest superstars in the world. They don't actually WANT players from their own league.
They want to transcend the local market, and pluck the best players from every OTHER league. And that level of branding and appeal can be used to cushion them from the problems of Barca or AMadrid winning the league, or whoever beating them in Europe. They are still a glittering, star-studded team.
The only Galactico that they ever signed that also weakened the competition was Figo. Nearly every other "Galactico" or similar was signed from another league - Kaka, Bale, Ronaldo, Rodriguez, Kroos, Beckham, Other Ronaldo, Zidane, Alonso, Di Maria, Coentrao, Modric, Benzema, Kovacic.
And Real gave been winning or coming second in La Liga for fucking DECADES. That's never changed. Now and again a smaller team will come along (valencia under Benitez) and upset the usual order, and lately A Madrid, but generally, Barca or Real are one or two. And always have been.
United have been buying players from Spurs - and wherever - for ages too; Carrick, Berbatov, Sheringham. But they have never had the lack of competition and unparalleled access to funds that Real enjoy. Chelsea and City have put paid to that. They can't simply pluck their best players from those teams, because they can't easily outpay them all, and they don't have the pull of Real or Barca. They've never been a side that wants to buy like that anyway. Perhaps Di Maria (or possibly Veron) was the first real attempt, and that was a fucking disaster.
Before that, they generally spent massive amounts of money on younger players., and I don't think it was an exercise in "weakening the competition" - Pallister, Rooney, Carrick, Ferdinand, Keane etc.
As for being a rich, sociopathic club, that isn't really the way they've ever behaved.
That's been the MO of the newly-rich cunts like Chelsea and now City. Before that, the interchange of top players, and/or buying surplus players to frustrate and weaken the competition didn't exist. And those two are the ones who do it most, still. And abroad, you mentioned Bayern, who DEFFO buy to weaken the opposition.
United have always been about trying to nurture youth and bring players through. About buying "potential" supplemented by the required amount of "battle-ready" players.
Clearly the rapid turn-around of managers and systems and philosophies has left them in a fucking mess, but they still did try and ensure their big purchases were mixed in with players that had the potential to grow and improve at the club; Depay, Martial, De Gea, Shaw etc.
And as for last summer, plenty of people and fans and experts said they did very good business indeed, bringing in Pogba, Bailly, Mikitikitaryan, massive zlatan.
As for buying Toure. Fuck's sake.