Building for the future on the defensive end this year does not make much sense to me personally, we already have young interior D lineman waiting in the wings, let us see what they can do before we trade more. Zach is 2-3 years from retiring and middle linbacker isn't like quaterback, you don't exactly need to groom the player for a few years, besides we have crowder who has shown that he will probly be a great player in this league one day and can take over zach's position. As for JT he has around as many years to retirment as Zach and we have a good young pass rusher in Matt Roth. And as for depth you can get that later in the draft if its really that much of a concern.