How many of those players you listed are defenders by trade? Cole, Kolo, Sagna, Clichy, Kos and Bellerin. I wouldn't count Vermaelen as he was already an established defender and Belgian captain when he joined us and as for Eboue, don't think you seriously mean that. Of those, how many would you count as truly world class, and by that I mean players who were consistently one of the best in the business for at least 2 or 3 seasons, if not more. Cole, Sagna and Kos. That's it.
So really, his record when it comes to grooming young defenders into WC talent, isn't all that great.