Working the angles, mathematics and physics of the game, Harden is like a scientist on the hardwood.
Meanwhile, Westbrook looks and plays as if he were the modern embodiment of bionic technology. The jumping ability, the nonstop motor, the ferocity, the intensity. He can go video-game mode at any time with his speed, strength and explosiveness, all while balancing functional precision. It's as if he were a menacing cyborg built in a Skynet laboratory.
But as Westbrook looks to adapt to his new team and new system in a new city, the question remains: Can the Rockets' bearded hoops scientist and recently acquired half-man, half-machine co-exist and contend for a championship?
The former Oklahoma City Thunder teammates think so.
"When it comes to me and James playing together, who's going to have the ball, who's not going to have the ball, it really doesn't matter," Westbrook said at the Houston Rockets' media day press conference.
He knows his triple-double streak is in jeopardy after three straight years and he doesn't care. And Harden, who grew up with Westbrook in the South Central Los Angeles area, agreed that at this point in both of their careers, it's no longer about padding the stat sheet.
It's all about the Larry O'Brien Trophy.
Figure It Out
Those are the most important three words facing Houston as it begins its much-anticipated Harden/Westbrook era.
Head coach Mike D'Antoni will have to manage the minutes that Harden and Westbrook play together. That scramble for symmetry will be the most important thing as the Rockets attempt to work through the growing pains of their evolution.
"James will be off the court about 13 minutes a game, so Russell will be out there by himself for 13-14 minutes," D'Antoni said. "Then Russell will be off the court about 16 minutes a game, so that's 29 minutes, more or less, they're not playing together. So we'll have one or the other on the floor at all times, and then we'll figure out the last five minutes.
"... But to be special, we got to figure that out."
The Rockets can't put a lot of stock in their dynamic duo's two preseason games, but what both showed against the Toronto Raptors was promising.
Harden stayed true to his 2018 MVP form, finishing with 34 points and seven assists in the first of the two exhibition games in Japan, while Westbrook, the 2017 MVP, chipped in 13 points and six assists.
The next game, they scored 22 points each and dished out a combined 13 assists.
For Westbrook, it was the first time he'd played since undergoing surgery to repair the fourth metacarpophalangeal (MCP) joint in his non-shooting hand and a scope on his right knee, so his conditioning isn't where he'd like it to be yet. But when he does get in game shape, he'll be a human defibrillator for Houston.
Familiar, Mutual Respect
To make their burgeoning (re)union work, the Beard and the Brodie will have to glean from the archives of their success as teammates, where they played in the 2012 NBA Finals and at the London Olympics that same summer.
"I can play off the basketball," Harden said. "... And vice a versa. Russ has played off the basketball, whether it is previously with myself or USA Basketball. He can do things necessary to win games. That's what it's all about."
To their credit, they are already touting the collaborative mentality they'll need to "figure it out."
"They both want to do this. So we'll just sit down and work it out," D'Antoni said. "... Just the vibe of being able to discuss things, the respect they have [for one another], will translate. We're in a good spot. Right now, it's great."
Harden led the league in scoring the past two seasons, breaking numerous records along the way. Westbrook has somehow found a way to make the triple-double seem pedestrian.
The fact that they are both willing to sacrifice whatever facet of their game needs to take a backseat is the logical first step to combating the narrative that their playing styles don't mesh.
"I can go be scoreless, and if we win, that's the best thing that ever happened," Westbrook said. "That's all I cared about, and that's all I ever cared about."
Their success as a backcourt duo will hinge on not only their adaptability to each other, but also on the challenge of maintaining the spirit of Houston's analytics-driven approach to shot selection.
The challenge for D'Antoni, then, will be to find ways to foster a communal vibe in the backcourt, employing a floor-general-by-committee strategy that's similar to the one he constructed for the Harden and Chris Paul experiment.
Critics panned the potential of a Harden/Paul backcourt from the outset, but they went on to win a franchise-best 65 regular-season games in their first year together and made it to the Western Conference Finals.
D'Antoni believes his new duo will be successful, too.
"It'll work itself out. You try not to overcoach it," D'Antoni said. "We need Russell to be Russell. We don't want to change him. He's an MVP. That's who we need. We need his bravura to be Russell. That's good enough."
Unlike the pairing with CP3, though, Westbrook will breathe new life into D'Antoni's offense with his elite athleticism. Couple that with Harden's iso-ball revolution in the half court, passing ability and three-point marksmanship, and the Rockets could have a scheme that balances both players' unique skill sets.
Additionally, Westbrook can take advantage of all the open space under the basket by attacking the cup for highlight-reel dunks or, if they collapse on his drives, kicking the ball out to open shooters behind the three-point line.
While the Rockets attempt to work through the growing pains of their evolution, fans will at least be rewarded with a show. Harden can be a wizard with the ball, and Westbrook's above-the-rim acrobatics are House of Highlights regulars.
Still, it's one thing to be must-see TV, but it is an altogether different thing to be a viable threat to win a title with juggernauts like the Los Angeles Clippers, Los Angeles Lakers, Denver Nuggets and Portland Trail Blazers in the loaded West.
That's a loaded word on any D'Antoni-led team: defense.
For all of the Rockets' offensive might, their deficiencies on defense have been their Achilles' heel.
Under former defensive specialist Jeff Bzdelik, Houston relied on a "switch-heavy" game plan. That philosophy worked initially, but with the loss of key three-and-D personnel, the Rockets slipped from a defensive rating of 105.7 in 2017-18, good for seventh-best in the league, to 110.1 the next year, putting them at 17th.
Longtime assistant coach Elston Turner will be running the defense now, and he'll have great defensive minds to help him spread his philosophy on stopping opponents. There's 2012 Defensive Player of the Year Tyson Chandler, Thabo Sefolosha, a member of the 2010 All-Defensive second team who can still be a lockdown defender, and defensive stalwart PJ Tucker.
While Westbrook isn't the elite defender that CP3 was, he ranked fifth in steals per game (1.9) last season and had the seventh-best defensive rating at 103. He was 10th in defensive rebounding percentage (28.3), a bonus for Houston as it looks to reverse its downward trend in the category after falling from fourth to 29th.
"I watched Oklahoma kick our butts twice last year, and there was this guy that would get a rebound and have it dunked on the other side when our guys started to run down the court," Rockets owner Tilman Fertitta said. "And I thought what would it be like to have this guy on our team?"
Then there's Harden. He has taken flak over the years for not exerting the same amount of energy on the defensive side of the ball, but according to Danuel House, he's ratcheted up his defensive intensity and improved his rotations, including weak-side help. He was also second in the league in steals (2.0) and showed a sneaky ability to effectively guard big men on the low block.
But this team won't have to rely on just Harden and his new co-star. The Rockets have Austin Rivers and Eric Gordon to pick up the slack on the perimeter.
"I'm looking forward to guarding the best perimeter player," Gordon said.
"I wanna be one of the best perimeter defenders in the league this year," Rivers added. "That's a challenge I made to myself. I told James and Russ whenever I'm on the floor, they're not going to be guarding the best player because they already have too much of a load."
"It's Going to Be Scary—Not for Us."
For D'Antoni, quality control will be job No. 1 as the season unfolds. He'll have to make sure all of the moving parts meet the Rockets' standards and improve over the course of the season.
He also must monitor Harden's and Westbrook's high usage rates (39.6 and 30.1, respectively). That means decreasing Harden's scoring load in the offense and finding ways to rest Westbrook more often because no one will be able to stop him from going 110 mph at all times. Postseason preservation will be important.
For Harden and Westbrook, two one-of-a-kind talents hoping to create something special this year, they'll need to continue to own their shared leadership responsibilities and perfect their on-court chemistry so opposing teams will have even more trouble picking their poison when they close out games together. But all of those facets remain promising, albeit unknown.
All that is certain is that it's the right timing of this union, not only because of their close-knit relationship but also because at this point in their careers they've evolved as players and achieved every individual accolade but haven't won it all as solo superstars.
"That's going to be the best part," Westbrook said. "When you have a friendship outside of basketball, you're able to communicate and understand each other."
Houston is approximately 1,370 miles from where Harden and Westbrook's basketball journey began, but it has the potential to be the place where they have a legitimate shot at finally wining a title.
All eyes are on the two teams in L.A., but Harden and Westbrook are putting the rest of the league on notice.
"It's going to be scary, that's all I can tell you," Westbrook said. "It's going to be scary—not for us."
Maurice Bobb covers the NBA for Bleacher Report. Follow Maurice on Twitter, @ReeseReport.