You made excellent points.
However, although 25 players seem a bit too many, I still believe that it could work. We have done it before, and there are many clubs who have about 30 players. But I get your point. I myself prefer a smaller squad of 23. Regarding playing time, they should at the very least get four full games (CDR) is that enough? I am not sure.
You are right about the age restriction, but I believe that players who are 21 cannot really develop anymore at Barca B, and they should go somewhere else. I did really enjoy your post.
Sorry for a late reply.
As I've mentioned in previous post if we can only guarantee La Masia kids 4 games in Copa then it's better to keep them to play regularly with Barça B and just call them up when needed. In other words we have two options:
1.) keep players in Barça B where they'll get around 3000-3500 minutes and practice with them for let's say 80% of the season but also play 3-4 games for the first team/train 20% with them
2.) train with the first team a whole season but only start 3-4 games/get around 400 minutes in a season.
Training is obviously very important but I think around 19-20 you should play every week even if it's against lower level competition. So if we can't give youngsters at least 1.000 minutes (and even that's low) in the first team then it's better to keep them in Barça B.
EV said he prefers to work with smaller squad so I think we'll have around 19-20 first team outfield players and 2 GKs. That way there will be an opening to call up B team players like Miranda, Oriol and possibly some others for CDR games or whenever we'll need them/EV will decide to give them a chance.
I think our goal should be to build a strong 18-man squad (best XI and 7 bench players) who could start at every moment. Looking at our projected bench we have:
1. Cillessen - If Jasper stays I don't think anyone here would be worried if he'd have to start an important game instead of MATS. If he'll leave then we'll most likely downgrade at backup GK position but hopefully we can still find a solid cheap veteran GK.
2. Lenglet - He'll have to adapt and show his worth first but I think he'll be (at least) a very good rotational player.
3. Roberto/Semedo and/or Digne - could use an improvement here especially at LB but I think it's ok. Some rich/top teams have troubles to find even their starters at one or both fullback positions let alone have a very good backup there. City has played with Delph/Zinchenko (both converter CMs) at LB last season, CB Nacho has filled in for Carvajal for Madrid...
4. and 5. two midfielders between Arthur, De Jong/Rabiot/whichever midfielder we might buy, possibly Roberto - we'll see what new guys will show but should be an improvement over last season
6. and 7. versatile winger (Denis) and backup forward (Paco/Munir) - we'll obviously need a (big) improvement here but I doubt it will happen this summer.
Then positons 19-21 are used for a mix between promoted homegrown kids (Alena) who will give their best whenever they'll get a chance and experienced veterans like Vermaelen who won't complain but you can always count on them.
Further, positions 22-24 can be used for Barça B players like Miranda and Oriol B. who are not officially part of the first team but can always be called up.
Then in a year or two those (younger) player from positions 19-21 move into the top 18 (to replace players who are not good enough anymore/too old/want to leave,...) if they develop well while players from positions 22-24 move into their previous spots. If we get a starting quality player from La Masia then great but we were spoiled with a golden generation and shouldn't expect this will happen regularly now so I'll be happy every time we'll produce someone that will constantly be a part of the match squad even if he won't establish himself as a starter. Hopefully Alena can become that player in a year or two but I think he'll be more in those 19-21 spots this year and I expect many people here will complain a lot about that. But it's all part of the process and he'll probably have to go through that as well.