I think the problem with that is that rescue cockers can be spread far and wide. The people involved in cocker rescue do a marvellous job, many of them take dogs in and care for them while homes are found. Not sure how one cnetre would work The other problem is there are always going to be cockers turning up in non-cocker rescue centres no matter what you do.
Probably in the same way rescues like Hereford and Worcester animal sanctuary operate whereby the majority of dogs are in foster homes. Cocker rescue operate in a similar manner through co-ordinators around the UK.
However cocker rescue will not take in a dog that has allegedly bitten/nipped so the small rescues take these in an assess them and retrain them in foster homes if they can then rehome them. I've known a number of cockers whereby this has happened and they are now in loving homes and have never had any problems in their new home (some dogs sadly get labelled when actually the circumstances or details are really suspect!). [H&W took in a 6 month old male cocker who'd allegedly bitten a child just before Christmas, there was no mark on the child though and 3 year old child had been left alone with this young cocker so mother doesn't know what happened! Thankfully H&W rehomed the dog and I 've met him recently and he's a typical non-aggressive exuberant young cocker who still would be OK with kids in the right home]