Signing sensibly
The van Gaal era saw millions of pounds spent—recklessly, it must be added—on several players. However, despite spending so much money, there wasn’t really any improvement in the way the team played.
For example, Angel di Maria was Real Madrid’s most important player from a tactical viewpoint. At United, however, he wasn’t even a shadow of himself as the former Barca boss couldn’t find a position that suited his skillset.
In fact, the Argentine, in an attempt that bordered on desperate, was tried out as a striker where he failed miserably. In the end, United’s most expensive signing was sold to Paris Saint German only after a year and with a considerable loss.
With Mourinho, the one thing that remains stagnant is his amazing ability to target and acquire players that fit his bill. He does thorough research on a player before signing him, hence the number of successful signings under his name are aplenty.