It seems like there's an hourly update as to who will be coaching the Texans, particularly on the defensive side, in 2011 (here's hoping there IS a 2011). The latest rumors involve Wade Phillips coming in as defensive coordinator, while Gary Kubiak and Rick Smith keep their current jobs. Even if it's not Phillips, a 3-4 scheme is probably a better fit for the Texans' current roster.
The primary concern for most people is the use of Mario Williams. I've even heard people say the Texans should trade him. Not only is that a bad idea, with his speed, quickness, agility, power and size, you'd be getting rid of the perfect weapon in a 3-4 scheme.
Williams could play a few positions in the alignment. First, and most obvious, he's the prototypical defensive end. Bruce Smith is probably the best 3-4 end of all time, and his frame is similar to Mario's. However, Houston's defensive end is a better athlete and would be an absolute nightmare for opposing coaches. The primary requirements of the position is to get after the passer and tie up blockers on passing plays, and set the edge on running plays. Williams has proven to be one of the best in the league at each of these in the more traditional 4-3.
Second, you could use him as a nose tackle in a 3-4 Eagle defense, or the 2-5 on passing downs. In this position, he could provide a quicker pass-rusher up the middle, or allow him to drop into zone coverage in the middle. Fritz Shurmer used to use this formation to throw off Joe Montana in the '80s, and it might work against Peyton Manning, Tom Brady and other quarterbacks who require a more sophisticated approach to confuse them.
Lastly, and the best fit in my opinion, is as an outside linebacker. Williams' aforementioned skill set would allow him to rush the passer from a more advantageous position. Since he would be coming from a wider slot and standing up, he would be able to use his speed to get around offensive tackles. That way, linemen would have a more difficult time getting their hands on him, which has been an issue for Mario since he came into the league. While Clay Matthews and James Harrison are sometimes neutralized by tight ends and running backs picking up the blitz, Mario would be able to simply bull-rush them deep into the backfield, or run them over entirely.
The scheme change would benefit others as well. Coming out of USC, many scouts thought that Brian Cushing would be a better 3-4 outside linebacker than playing on the strong side of a 4-3. Technically, he was better at running the arc and getting to the passer than his teammate, Clay Matthews. With Cushing's strength, range and athletic ability, I could see him as a poor man's DeMarcus Ware.
With Williams and Cushing on the outside, the Texans would have one of, if not the, best outside linebacker combinations in football.
The most important benefit for a change to the 3-4 is the effect it has on the secondary. The 3-4 allows for more creativity and pressure on the quarterback, which decreases the amount of time cornerbacks have to stick to their receivers or sit in zone coverage. Thus, much less is expected of the defensive backfield, which would really help the Texans and their current issues on the back end. Remember, the Steelers defense has been one of the best in the league, in spite of average cornerback play for the past seven or eight years.
As for the other positions, here's how I see the current Texans lining up in a 3-4 scheme. Players with asterisks next to their name would have to be upgraded immediately for the Texans to be an above-average 3-4 unit.
Moreover, with players like Connor Barwin (OLB), Mark Anderson (OLB) and Earl Mitchell (DE) coming off the bench, you would have some depth with guys who are probably more suited to their 3-4 positions than their current ones in the 4-3.
There's no doubt there would have to be some changes, though. As mentioned above, significant upgrades would have to be made for this to work, most importantly, a strong, space-eating nose tackle and a free safety with some range. Currently, the Texans have answers for neither on the roster. But, with their draft position improving weekly, the upgrades may come easier than one would have thought three or four weeks ago.
The most difficult position to replace would be nose tackle. Strong, 6'2", 325-pound behemoths willing to sacrifice statistics and take on multiple blockers just don't grow on trees. It's the reason guys like Vince Wilfork, Casey Hampton and Kris Jenkins are so sought after.
Unfortunately, there are only a few options in the 2011 draft that would help immediately. Probably the most notable would be Marcel Darius out of Alabama. He has the frame to gain weight and would probably have to do so to stand up to the pounding he'd take. However, Paul Soliai (Miami), Gabe Watson (Arizona), Cullen Jenkins (Green Bay) and Johnny Jolly (Green Bay), among others, are suitable free agents that could fit in while searching for a younger option in later drafts.
A playmaking free safety would probably be easier to get in this draft. Most notably, Rahim Moore out of UCLA would be a perfect fit. He has the range and ball skills that would allow him to play center field like Troy Polamalu and Ed Reed. Taking him in the top 10 would be a reach, but you could trade back and still pick him up in the late teens, early 20s.
With the 2010 performance of the Texans defense, just about anything would be an upgrade. But, the way they are currently built, a switch to the 3-4 wouldn't be difficult. As a matter of fact, the way they've drafted over the past five years, it seems as though that was the goal, and leading the way would be Mario Williams, who will be the most versatile player to ever play in the scheme.