I'm not certain what Spears would have done in Marinelli's DL scheme, especially if he didn't get fat due to Wade being the Head Coach. Obviously, Spears would have been a 1-tech not a 3-tech.
It was BP who loved big players on defense.... he liked spears more then ware.
Wade liked pass rushers across the board and he wanted pure playmakers.
I think Spears was just a big guy who wasnt athletically elite.
The added weight made him a space eater but he was never a pass rush guy at all.
Hatcher and Ratliff could both really rush the passer, Spears simply couldn't. Don't think any coach is to blame for that.
Here is the SI 2005 draft profile on Spears who was listed at 307 then.
POSITIVES: Well-sized, athletic defensive lineman who offers a good degree of upside potential. Forceful up the field, plays through blocks and quick changing direction to pursue the action laterally. Plays low with leverage, balance and body control. Easily moves to the sidelines, can drop off the line of scrimmage and make plays in space or in any direction of the field. Displays an explosive inside move, reads the action and quick locating the ball.
NEGATIVES: Must improve his tackling technique. Rather easily held up at the point by ordinary opponents. Doesn't always seem in a hurry to get involved in the action or pursue the play if it.s not in his immediate vicinity.
ANALYSIS: An outstanding athlete who, when on his game, can be a difference maker, Spears offers early first round physical skills yet has late first day motivation. A tough lineman to block, he is a disruptive force rushing the passer, defending the run or even playing in space. Could be a perfect fit at left end in a conventional defense or as a two-gap lineman, but must start to apply himself on a consistent basis to ever reach the potential he possesses.
to me that's basically Kelcy.