The Houston Texans are good. They're leading the AFC South by two games after Monday's 34-17 victory over the rival Tennessee Titans at NRG Stadium. But they've yet to reach the rarified air where the New Orleans Saints, New England Patriots, Kansas City Chiefs and Los Angeles Rams reside. 

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The Texans' eight-game winning streak does serve as a testament to an improving football team that became the first in NFL history to achieve an 8-3 record after losing its first three contests.

Who have the Texans really beaten, though? 

The combined record of Houston's opponents during its streak is 40-48 overall. Yes, the division-leading Dallas Cowboys are included as well as a few teams playing well at the moment, yet none of them can be described as elite. 

Houston has faced one team, the Patriots, with seven or more wins this season, and it lost the season opener to Tom Brady and Co. The final five games will look similar to the previous 10. Only the Indianapolis Colts have a winning record, and the Cleveland Browns, hapless New York Jets, reeling Jacksonville Jaguars and disappointing Philadelphia Eagles round out the final five. 

Obviously, a team can't be blamed for its schedule. It can only beat the squads the NFL schedule-makers place in its way. Safety Tyrann Mathieu made it clear the Texans don't care who they beat as long as the result remains the same: 

However, a suspect schedule can hide deficiencies. This is why the Texans should be concerned. 

Quarterback Deshaun Watson, wide receiver DeAndre Hopkins, defensive end J.J. Watt, linebacker Jadeveon Clowney and Mathieu are stars. No one will deny this. Each one can take control of a game at a moment's notice. The headliners aren't the issue, though. It's the other cracks found within the roster that place Houston a notch below the league's best. 

The offensive line remains a work in progress. Left tackle, in particular, is a disaster.

Simply put, Julie'n Davenport is the game's worst blindside protector. The second-year blocker leads the league in penalties assessed (13) and accepted (10). As of two weeks ago, Davenport was tied for the most pressures surrendered with 42, according to Pro Football Focus. 

The 23-year-old lineman has all of the physical tools teams want at the position and can be overwhelming at the point of attack in the running game, but the Texans are lucky Watson hasn't been destroyed by edge-rushers this year, though his mobility has been a big reason he's survived.

Opponents will continually attack an offensive line's weak link. Davenport fits the bill. His performance has been so poor the other four linemen tend to receive a pass even though none are above-average blockers. 

Even in a decisive victory, the Texans allowed four sacks. Pass-rushers have now gotten to Watson 37 times—which falls one behind the Cowboys' Dak Prescott and New York Giants' Eli Manning for most in the league. 

What will happen in the playoffs when Houston's front five faces the Chiefs or Pittsburgh Steelers, who both rank in the top three in sacks? Watson will be running for his life—more than usual, that is. The Chiefs' Patrick Mahomes and Steelers' Ben Roethlisberger have been sacked one fewer time than Watson when their season totals are combined. 

Protection is a problem. It's not going to change, either. The Texans are talent-deficient up front. Watson has already dealt with a chest injury this season.

Houston's best hope is to establish a strong running game to build early leads and better protect Watson. A franchise-record 281 rushing yards against the Titans is a good start. Or, head coach/play-caller Bill O'Brien can get creative by using Watson's mobility to its fullest to prevent the signal-caller from getting destroyed. 

The league's best teams feature strong offensive fronts. Houston doesn't. 

The number of weapons Watson has at his disposal is suspect as well. Obviously, Hopkins is fantastic. Lamar Miller is a home run threat at running back. That's it. 

The Patriots feature tight end Rob Gronkowski, running backs Sony Michel and James White and wide receivers Josh Gordon and Julian Edelman. The Saints are nearly unstoppable to stop with wide receiver Michael Thomas, rookie Tre'Quan Smith, wild card Taysom Hill and running backs Alvin Kamara and Mark Ingram II. The Rams lost wide receiver Cooper Kupp to a season-ending injury yet still have Brandin Cooks, Robert Woods and the game's best running back, Todd Gurley. The Chiefs are a scoring machine with Kareem Hunt in the backfield, Tyreek Hill blazing past defenses, Sammy Watkins also stretching the field and tight end Travis Kelce doing work over the middle.  

Houston lacks the firepower to go punch for punch with the league's most potent offenses, even after acquiring Demaryius Thomas from the Denver Broncos prior to the trade deadline. 

Will Fuller V's season-ending ACL tear in Week 8 didn't help matters. His replacement, Keke Coutee, who caught two passes Monday for 14 yards, suffered a hamstring injury, according to the Texans' official site. Both are vertical threats who can take pressure off Hopkins and Thomas when healthy. 

A poor offensive line coupled with inconsistent weapons beyond the team's top options have led to poor red-zone play. 

"Yeah, we're in there, but we're not getting anything done," the head coach said last month, per the Houston Chronicle's Aaron Wilson. "We just have to continue to work at it and we have to figure out what we can do to get the ball in the end zone because it's not getting done right now."

The Texans entered their Week 12 contest as the NFL's third-worst red-zone offense. The defense isn't any better when opponents near the goal line: 

To the team's credit, the offense converted all three of its red-zone trips into touchdowns against the Titans, while the defense didn't allow Tennessee to score a touchdown either time it entered the red zone, including a fourth-down stop on the 3-yard line (a direct handoff to the tight end?! C'mon). 

Improvement can be seen in crucial areas. Any regression will place the squad at yet another disadvantage. 

"I still think we can be more consistent," O'Brien told reporters. 

Two tiers have formed in both conferences. The Saints and Rams are the NFC's best, and the Chiefs and Patriots are the AFC's equivalent. The Texans fall below that level and may even be a half-step behind the Steelers and Los Angeles Chargers. 

However, Houston's continued growth this season bodes well in the short and long term. Watson told reporters after the game, "We're sitting here 8-3 and have the opportunity to do something special." The pieces are in place to make the postseason this year.

Once the offensive line is fixed, another weapon or two is added and red-zone efficiency improves, the Texans will find themselves among the league's elite. They're just not there at the moment. 

Brent Sobleski covers the NFL for Bleacher Report. Follow him on Twitter: @brentsobleski.