Lauren had peak campbell/toure then keown and if i remember (an albeit aged) adams too
The best of the lot that Sagna had in his years was Mert/Kos and even there Kos was never a brainfart away even at his best while Mert took 2 minutes to turn.
And that was the best, amongst the worse and there's plenty to choose from is a washed up cambell combo with silvestre, Kos-Squillaci, Senderos-Djourou and to cap it off Almunia became first choice GK for 3-4 years from 2007 onwards just some months after Sagna signed.
I think you have to go back to the adams/bould/keown days for a cb pairing better than Gabby/Saliba though. Campbell was immense but Toure wasn't IMO near Gabby/Saliba.