as for having a lot of cornerbacks, all i have to say, is that i'd rather have quality over quantity. as of now, the patriots don't have quality. brandon meriweather might be a nice hybrid cornerback and safety, but safety is his natural position...
although the linebackers are aging, i gotta say, rookies jerod mayo, shawn crable, and bo ruud could be a solid group in the future, when tedy bruschi, mike vrabel, and adalius thomas' careers are over.
the best unit of the patriots defense has to be the defensive line, which has a nice mix of proven veterans.