You forgot the part where the backups - young backups - were bought with the intention of being future starters. Great approach buying young talents slowly integrating them into the squad. Denis is back (great decision to let him leave and develop!), Rafinha was brought back, we can get Adama and Halilovic back if they develop like Denis did. Munir and Samler can comeback as they wont be sold without buy back option or maybe even only loaned. Going the "Denis"-route is the right decision. If they develop and prove themselves like Denis did, they'll be back. Only bad decision was letting Grimaldo go without buy back. But Digne looks promising, so it doesn't hurt that much. Unless you got this thing where players have to be Spanish or Catalan. For me, Digne is fine. I don't see the problem.
WORD! And as for Munir and Samper, they will get exactly what they need: a season (or two?) of playing hopefully regularly in a team, who is still strong enough to be fighting at least for a midtable finish, if not even for Europe competitions (with a little luck). So it'll be a great experience for them, Valencia is exactly the kind of perfect team quality-wise that Celta (Rafinha) and Villareal (Denis) are.
Really hoping this deal goes through, Alves would also be a great replacement for Bravo, MATS would finally deservedly get to be 1st choice, the possible ruining of team harmony about the 1st choice GK situation would be fixed, and we'd also have a strong and i think a little more reliable backup for MSN than we have now. Hopefully Munir can also become that after playing regularly on loan. Cause even though he really impressed (me too) during this pre-season, it's easy to imagine the inconsistency to come sooner or later, and that's where we'll be fucked, especially if one of MSN gets injured for a couple of weeks or worse. Paco is the obvious upgrade right now, while a loan will do great for Munir's consistency and future potential too. He (and Samper) will return just like Denis did, and they can be another great squad players, but quality enough to properly challenge our current first choices right from the get-go and then sooner or later become actual starters, just like all of this summer's bought players are.
People complaining about buying backups...these backups actually have the potential to be our 1st choice in a matter of a couple of years, we're in a position to have a kickass lineup even after Iniesta, Suarez, even Busquets and Messi stop playing. I imagine it to be something like this: Ter Stegen-Roberto-Marlon-Umtiti-Digne; Gomes-Samper-Denis; Halilovič/Adama(Dule!?)-Paco-Neymar.
In recent years, with Iniesta getting injured even for 2 weeks, we would be in panic mode, but now? Not worried at all, Denis is fantastic, and we still have Gomes, who is yet to play! The same will go for Suarez, if Paco comes. Even though there's still the obvious lapse in quality, it's still not as big as it would be a season or two ago. We have fantastic squad depth, which will only get better, if we manage to get Alves and Paco, GK and attack positions would then be safe in terms of depth too, like midfield and defence (the exception maybe being the RB position, but not if Roberto keeps performing) already are.
Finally we won't be shaking our boots after every injury, apart from that being Busquets and Messi, who are practically irreplaceable in any case.