Kenyon is convinced United have overpaid for a raft of their signings.
Kenyon told the Business of Sport podcast: “How many times have we seen a team that has spent a fortune in the summer with a coach that plays one way, and when it comes to October, they bring in another coach who plays completely different football and it isn’t going to work?
“That’s not about money. That’s stupidity. There is way more to it than spending money to become successful. You don’t have to pay somebody £400,000-a-week. That’s your choice - but you can’t buy success.
“One thing I learned from (Sir Alex) Ferguson was that if anyone said ‘I’ve been offered more money by Real Madrid ’, he would tell them to go to Real Madrid. You don’t come to United because we pay the most money. We paid good money. We were more than competitive - but we never ever paid the most.
“If you aren’t smart enough to get players to come to Manchester United for less money than somebody else then you’re not doing your job properly.”