Now, if we'll buy De Light, we will have:
1. a club icon and an icon of Catalonia and independance (Pique) who plays as a Goat this season. You can't bench him in the next 2 years, I guess.
2. Lenglet, who is young and awesome this season
3. Umtiti, who is young and was called by people here: as the best CB in the world last season
Now, let's move emotions and bias for a second.
How exactly are you guys planning to rotate these 4 players?
The only option is to rotate 4 defenders in EVERY single match.
But then... you need chemistry and automatism in the defense also, which can be accomplished only with playing one defensive duo more often.
Pique and Lenglet played for 1 season together and they now have a good chemistry.
Pique and Umtiti played in the last season and had a good chemistry, but now they haven't played together for half of a season.
Also, short term: Pique is heavy and slow and De light also.
Those two can't play together, right?
De Light could play with Umtiti and Lenglet.
But then, what Wolfe mentions often: you need an older guy and a kid together so that an older guy can teach and lead a kid.
Who will teach De Light? Lenglet?
So, I am not against De Light.
I just think that he is NOT THAT GOOD in THIS MOMENT.
Plus, his signing will bring a lot of practical problems for a coach in terms of rotations in defense and making all 4 guys happy.
"The best" option for us would be if one defenders would get injured for 6 Months, then 3 guys would play a lot.
If all 4 guys will be fit, there will be a lot of problems and unhappy players (and Barcaforum fans).
Good points here. CB (alongside GK) is a position where most coaches don't really want to change much if not needed (injuries, suspensions). Having Pique, De Ligt, Umtiti and Lenglet looks absolutely great on paper but could also bring some of the problems you mentioned. Keeping the younger trio for more than 2-3 years would be hard enough but we'll still have Pique for the next two seasons.
In ideal world we would buy De Ligt in 2020 or maybe even 2021. But in reality it's now or never if we're seriously considering him as a future Pique replacement. I think we'll get him so EV will have to find a way to keep all four CBs "happy" and in form. In worst case scenario Pique could go back to thinking more about his off-the field stuff than football, Umtiti's injury problems won't go away, MDL will have troubles to adapt and Lenglet won't play on the same level than this season. So having 4 "great" CBs on paper wouldn't help us much in that case but maybe we would be "lucky" enough two of them would be in good form/healthy/focused enough on football at the same time so we could somehow go through the season without suffering too much. Still better than counting on Murillo (not good enough), Vermaelen (old and injury prone) or Todibo (talented but very very raw) as your CB depth/rotation though.
But now let's assume Pique stays focused and plays on the same level he did the last 3 months or so. Lenglet stays consistent as well. Umtiti is back to his pre-injury form or at least close to that. And De Ligt has no problems to adapt. What should EV do in this case? Personally I think keeping two CB pairs would be the best way. If Umtiti is back to his old self I would assume he would play alongside Pique in most big/important games. And we could play De Ligt-Lenglet in easier games and in CDR.
I think De Ligt is very experienced for his age and don't really need a "mentor" during the games so you don't need to pair him with Pique but obviously he could learn from him on trainings. But if MDL-Lenglet would play really good they will probably think they deserve to start some games at least against Sevilla or Valencia if not in El Clasico or against AM. How should EV handle things then? Or if Pique is injured/suspended for a big game, do we play MDL with Lenglet (who he's more used to play with) or alongside Umtiti (who might be a top 3 CB in the world again by that time but has bad/not proven enough chemistry with MDL)?
In reality, things will probably be somewhere between the worst and best case scenario mentioned above (still hopefully closer to the best scenario) but some problems and tough decisions for EV will stay and yes, it could lead to unhappiness among the players. I won't mention the fans because they always find something to complain about.
Another way to get minutes to MDL is to sub him on for Pique in 2nd half when we're up 2-0 or more but how many times could we do that during the season? 3-5 times, maybe up to 10 times but we would risk upsetting Pique if he would be constantly subbed off. And well, it's also not easy for CBs to come into the game off the bench. But I think both MDL and FDJ will get a lot of their minutes off the bench at the start of the season with occasional start here and there. People on barcaforum won't like this but they'll have to play and deserve their way into the lineup like Arthur did this season. I think they are both aware of that and willing to accept the challenge.