Oh, neither of us have enough proof? REALLY NOW?
Okay, I'll list you some English centre backs that have excelled.
1. Curtis Davies. He's been a rock at the back for Hull, with one of the highest tackling and interception rates in the Prem and a tiny amount of errors.
2. Phil Jagielka. As per usual, he's been quietly excellent. Solid, consistent, hasn't had a bad game this season. In the Chelsea - Everton match he was Everton's best player, so you're talking *****. High amount of interceptions, only been dispossessed twice this season.
3. James Tomkins. Exceptionally good in the air and on the ground, a great distributor and the leader of West Ham's defence despite being so young still. Excellent tackle success rate.
4. Steven Caulker. Been in great form for Cardiff. A beast in the air, quick and agile. Great aerial duel success rate.
That's four. The likes of Dawson and Williamson have also been pretty good when called upon. Just because you can't name any English CBs outside the most recognisable ones doesn't mean the rest don't exist. If you want more proof, I can actually start throwing stats at you, but like I said earlier, the burden of proof is on you, not me, so it should be irrelevant anyway.