I watched a documentary the other day about our trip to Carlisle last July. There were a couple of dickheads with his name and number on the back of their 09-10 tops. Incredible.
That'd be a massive wrong-fit. Colo and Kaboul share some of the same weaknesses.
Williamson and Colo as a partnership are OK. Not great, but OK. No point in breaking them up for a 7/10 defender like Kaboul.