Re: more team speed at lb soon...
On passing downs the NT will come out and the nickle back will come in. Instead of a 3-4-4 look the Texans will have more of a 4-2-5 look. The OLB's will be more like DE's and the DE's will be more like DT's. However, out of that look anyone can end up doing just about anything. The OLB's can drop back into pass coverage. The ILB's can blitz. Even the DE's turned DT (Walker and Smith) might occassionally drop back in a zone blitz scheme where they cover an area and someone else blitzes. Any of the DB's could also come blitzing.
The more flexible each individual member of the defense is, the more unpredictable the defense as a whole can be.