What has he done compared to FDB who clearly is in our radar
This.
Allow me to sell Cocu to you :
Phillip Cocu, age 45.
Replaced Penis Advocaat at the start of the 2013-14 season, took over a PSV side that had just finished 2nd to Ajax and Lost the Cup Final to AZ.
A shaky start saw him take them to 4th and 3rd round cup exit, CL exit to Milan in the Play Off and a disappointing Europa league group stage exit.
https://en.wikipedia.org/wiki/2013–14_PSV_Eindhoven_season
Then a Depay inspired PSV smashed it in his 2nd season, very impressive 17 point winning margin, 92 goals scored.
https://en.wikipedia.org/wiki/2014–15_PSV_Eindhoven_season
And then this season they again managed to win the league, despite the sale of without doubt their 2 best players in Depay and Wijandum
https://en.wikipedia.org/wiki/2015–16_PSV_Eindhoven_season
Notice the GA for Ajax both seasons.
You want?