One IS a serious, but polite Frenchman with a Germanic air who lives for football. The other is a laid-back, slightly arrogant, jokey Dutchman who lives for football, his own designer label, television punditry and the 19-year-old girlfriend who follows two wives and has just been delivered of his fifth child. Ruud Gullit also does pizza ads.
The contrast is stark: John Lewis and Armani, professor and the playboy, IQ and GQ.
This season, Arsenal are leading Chelsea 2-0 after a league win in September and the first-leg victory in the League Cup semi-final 10 days ago. Tomorrow sees another league meeting; and February 18th, the semi-final denouement.
Overall, the managerial records of Arsene Wenger, after 15 months in charge, and Gullit, after 20 months, are much the same. Chelsea's goals-for-and-against column betrays the more cavalier approach, but, while Arsenal finished third last season, Gullit has the edge in silverware.
Only five foreign managers have made it to the English top flight. Ossie Ardiles and Aston Villa's worst signing before Stan Collymore, Dr Jozef Venglos, flopped. Christian Gross is heading that way. So what makes Wenger and Gullit so special?
They say the dreadlocked one is cool. But listen to a self-styled expert on the subject talking about Wenger. "He doesn't bully his players into performing for him," says Ian Wright. "He just looks at you through those big specs and says: `You are not letting me down, or your team-mates, or the club who pay your wages or even the supporters. You are cheating yourself. Can you live with the fact that you are cheating yourself and failing to maximise your ability?' That's not just brains. That's man-management."
Far from cool, Gullit's method of letting people know they are not performing is decidedly cold: he drops them, and with little explanation.
Players are silently urged to look at themselves. Gullit met their resistance to his idea for a squad system with the same hatchet diplomacy: anyone who did not like it could go.
Gullit's argument that the squad system keeps players' legs and minds fresh is countered by continuing doubts about leaving out Mark Hughes here, or Gianluca Vialli there.
But Chelsea currently sit second in the Premiership and pretty in the Cup Winners' Cup and the Coca-Cola Cup. It must be working.
Not that Gullit changes his team as much as is made out. He rotates his four strikers, but otherwise, injuries and suspensions permitting, he employs a cast of regulars.
Wenger would play his best team at all times if he could, and tactically, also, the prof is more rigid than the playboy, a solid 4-4-2 man, rightly praised for re-introducing the passing game to Highbury.
Last season, Gullit, a passing man himself, switched between 4-4-2 and 3-5-2, though using 4-4-2 this season backfired with the team's recent poor run and he decided last week to revert to 3-5-2.
It makes sense. His personnel are better suited to the latter as Frank Leboeuf is a sweeper not a centre-back, while Graeme Le Saux and Dan Petrescu are better playing at wing-back than stuck as defenders or midfielders.
Critics of Wenger will say that the absence of Dennis Bergkamp has exposed Arsenal's shortage of creative options and also the lack of ready-made striker cover given Wright's penchant for injury and suspension, plus his recent dip in form.
Whenever foreign managers are mentioned, the word "diet" is not far behind. But Wenger and Gullit do not eat from the same plate on this.
The Frenchman has employed nutritionists and asked the players to look at their whole lifestyle, from drinking alcohol "right down to putting no sugar in our tea or coffee on match days because it lowers our energy levels," says Wright.
But when Gullit took over at Chelsea, he sacked the reflexologist, the faith-healer and the nutritionist. He knew a lost cause when he saw one.
"They are too accustomed to the sausage," he said. "They must have it. What can I do?" Gullit just trusts the players to look after themselves, though he does employ a fitness coach.
Of course, the pair's pursuit of success has been helped by the fact that they inherited relatively successful teams and fat chequebooks. Gullit also has a special pulling power as a world star.
Both have also experienced the pressure at the game's top levels. But to manage successfully in the Premiership, a foreigner needs two other key attributes. First, an understanding of the special ingredients that go into English football. On the pitch, that means pace and commitment, but style, too; lots of games and none of them easy.
Before joining Arsenal, Wenger was a huge fan of the English game and studied it closely. Gullit was a Chelsea player for a year before stepping up.
The second item in the foreign manager's Premiership survival kit is a command of English good enough to put over his ideas and personality to the players and the media.
The prof and the playboy have all this. The fact that Christian Gross does not may explain a lot.
