It's an easy idea, isn't it? Sell your best player for £100m, and sign two players worth £50m. Or three worth £33m. It's simple. You see it on Twitter all the time: "For one Maguire, you could get two Davinson Sanchezs, or a Sanchez and two Heung Min-Sons!"
The reality is somewhat different. For every time clubs find a diamond in the rough, you've a dozen Paulinhos in the way, shooting with their toe against Burnley to showcase that the Gareth Bale money really should've gone elsewhere.
But it's not just Spurs that do this (although they do feature quite a few times). It's become abundantly clear that replacing a superstar is not as simple as just buying someone in the same position for a similar amount of money. You have to think about squad dynamics, tactics, and simple questions such as, "Do they actually know how to play football?"
As a fan, it's very easy to get excited when you bring in a whole host of expensive signings. A lot of the time, it doesn't work out the way that you'd planned.