Data is only worth following if the underlying philosophy and style is consistent and pursued without abandoning and changing it every few years. This is especially crucial if financial constraints force you to shop for players who will only come good 3-4 years down the line, which has been the case for us in recent years. There's little point signing them if it 3 years you're looking for completely different data sets.
This is why several of our youngsters haven't pushed on at all this season. Of course injuries need to be taken into consideration, but won't account for the whole story.
Take Pape Sarr as an example. Seemed to be progressing nicely under Ange because he wanted a box to box midfielder who could run all day and press the opposition in their third, two things Sarr is well above average at and has positive data for. He ranked among the highest players in the PL in interceptions, shots, and touches in the opposition third.
Then we sack Ange and appoint Frank, whose philosophy for his midfielders is completely different. Now Sarr is being asked to protect the defence in a low block and feed quick and accurate passes into the wide attackers. Lo and behold, his data shows that he isn't very good at either of these, which is why he couldn't hold down a place in the team at all this year and had put in numerous woeful performances in which he looks lost. He is ranked as one of the worst midfielders in the league for progressive passes, getting dispossessed, and progressive dribbles.
So there you go. Identical data tells two completely different stories, it all depends on who narrates it.
And because we change narrators like underwear, any spreadsheet Lange wants to pleasure himself to is by definition unusable.