Really good test engineers are hard to find and are at least as valuable as good design engineers. I always say that "a reproducable bug is half fixed", so getting reproducable bugs from testing cuts my work in half. Testing is a totally different mindset: design engineers try to make things work, while good test engineers try to do the opposite.
I once worked with a great test engineer named Bob. He was a really nice guy, except that he was positively sadistic when it came to making products fail after they had been "blessed" by design engineering. Then he would come by with a little smile and say "Betajet, I found something Interesting." "Interesting" of course meant more work for design engineers, but he had done the hard part.