Have no idea what will happen when we have all of Kos, TV and JD fit and available. Fairly certain Kos was bought as a starter, but the form of JD must give Wengie selection problems, at least initially. Either way I am happy we have them all. Lots has changed since pre season when a bunch of people wanted to get rid of Djourou ASAP!
IMO TV is the best CB we have. Not so sure that him and Kos will work that well together though. They are both prone to rushing into situations, and they both want to be pro active trying to get ahead of the forward and break up play. One player like that is really good, but both CBs? This may of course not be a problem, but it could be.
Another aspect to take under consideration is that JD and Kos work well as a pairing. Do you automatically break that up when TV is fully fit? (Which for me probably means next season). Wengie persisted with a malfunctioning CB pairing in Gallas/Toure because they were individually our best CBs. Will he think differently this time around? (And I´m not saying that a Kos/TV pairing automatically means trouble).