of course. But if you are releasing guys you have to replace that depth. If you draft well enough to do that you are golden - but then again, if you draft really well in the NFL you are golden - period. It solves basically all your problems. If you can't draft well enough to replace guys then you're not in such great shape because you're going to have to turn around a spend that cap space signing guys to fill lholes or risk not having injury depth. An example would be what the Lions did a few seasons ago when IIRC correctly, they recovered cap space by letting Reiff walk but then had to turn around and sign Wagner for virtually equal money. So cutting guys is fine, but only if you can draft well enough to replace them cheap - so it's still the drafting (or scouting UFA etc) which is the critical piece. Being able to cut guys is a contingent option. It's not something you can count on on a regular basis unless you are doing other things well.
That said, the Lions are in pretty good shape ....this year....