I think their issues recruiting defenders at Barcelona is massively overblown.
Txiki's record at Barcelona is this -
Rafa Marquez €5m - Excellent signing.
Gio van Bronkhurst €2m - Excellent signing.
Juliano Beletti - €3m - Decent signing, scored a CL final winning goal.
Sylvinho - €2m - Very good 3rd choice player, won loads.
Zambrotta €14m - Didn't live up to the hype but was sold for €11m after 2 seasons.
Thuram €5m - Maybe overpaid a bit for a 32 year old back up player, but he was a big name and pretty good.
Abidal €15m - Excellent signing, especially after Pep worked some magic on him.
Gabriel Milito €20m - Had a horriffic 2 year long injury just after signing. Can't blame Txiki.
[Pep joins here]
Gerard Pique €5m - Hard to imagine a better CB signing given the price and all he achieved.
Martin Caceres €16m - This was a bad one.
Dani Alves €35m - In Pep's opinion the best RB of all time, one of the most important players in Barca's greatest side.
Henrique €8m - Youth prospect signing that didn't work out.
Maxwell €4m - Good back up to Abidal, sold on for the same price at 32 after 3 good years.
Chygrynskiy €25m - The infamously bad one.
Mascherano €19m - Excellent signing, was CB for several CL wins and 4 or 5 league titles.
Adriano €10m - Good signing, very capable backup during his time at Barca.
Pep carried on with one more before he left in 2012 -
Jordi Alba - €19m - Excellent signing.
The majority of the signings were *very* good ones, with a couple of speculative ones the didn't pan out, and 1 or 2 bad ones. I think the fact Barcelona didn't need to sign a first choice defender after Txiki left until 2016 shows he left them in really good shape with Pique, Puyol, Mascherano.