If both Lewa and Koulibaly are available for 40m and we can only take one of them who would you guys choose?
Personally at the stage of rebuild we're in I'd avoid both of them tbh. We're not just a CB or a striker away from being a CL contender so spending money on older guys who can help us immediately would make sense. Both of them would clearly be an improvement over what we have and possibly help us to challenge Real in La Liga but is it worth it longterm? We already have too many old legs in the team (who are playing waaaay too many minutes which is more concerning), should we really add another player or two who will need to be replaced in 2-3 years?
We should also keep in mind that most players, even those who have proved their quality in other teams usually need at least a season to adapt to our system (and some players never really manage to do that) so in best case we can probably get a good season or two out of those guys. And then they would have no re-sell value at all. If we gamble on someone younger and he flops at least we can still get some money for him (selling "flops" from now on should be easier as Laporta won't give them crazy wages like Bartomeu, at least not in near future).
If I'd have to choose between the two though I'd probably take Koulibaly who is younger, should have a few more years left in the tank and I think he would also adapt easier and faster. But in the end it really comes down to what alternatives we have at both positions. Do we take Lewa or take a risk on someone like Darwin (who as you probably know I'm a big fan of)? What other CF that would improve what we have (so not likes of Morata for 40m even if I'm affraid Xavi will push for him again) can we realistically get?
We've had that run of games when attack worked well and IF (and that's really big IF) Ansu stays fit and Ferran will adapt to the club and become more consistent then we can probably go through another season with what we have upfront (another question is of course a RW position. Will Dembele stay or do we replace him with Raphinha? Ideally I think Dembouz renews on a 3-year contract with lower wages and we also sign Raphinha but it's probably unlikely) and hope a few new forwards wil emerge (or further prove themselves if some of them are already on our radar) and we can sign one of them next year. A fit Ansu, Auba, Ferran, Memphis, Dembele and/or Raphinha is not ideal but also doesn't look bad. Clearly much better than what we've had at the start of this season.
OTOH defense has been problematic for years. We need to find a longterm partner for Araujo. They gave Christensen a starter wages (at least imo) so do they really see him only as a backup/replacement for Lenglet (won't even mention Umtiti) who is barely playing? Or just a more expensive replacement for Garcia as a 3rd CB? It shouldn't be hard to be better than any of those guys but Christensen will need to prove that obviously. Pique is also still around and like his off the field stuff or not when he has played he was more than ok in recent months so I'd expect him to still have an important role next year as well. Injuries have caught up with him though so he'll play significantly less than likes of Busi and Alba.
There are younger CB options than Koulibaly available though. Kounde would probably cost twice as much (so while he's still my prefered CB don't think he's a realistic target) but there are also cheaper alternatives. Some names like Lisandro Martinez are linked to us but there are surely also other CBs in smaller clubs in Ligue 1/BL/Serie A that most of us probably don't know much about but are worth considering (one of them I hope we're keeping an eye on is Piero Hincapie). Hopefully our scouts and Alemany/Cruyff know them. Would be great to get another bargain like Araujo but we probably can't count on that. So we should carefully evaluate our targets and bring the best one available and affordable. Well, evaluation process should be close to over now with season ending and people in Sporting department should have more than enough information about the players they're interested in. In opposite to general opinion I don't think our scouts were ever really that bad, we just lacked quality decision making at the top (one of the reasons for that was having too many cooks in the kitchen and consistently making changes in the SD). Now it's time to make smart decisions. More than ever.