Whatever else has changed, two things have remained the same in recent years.
Arsenal do not win league games at Old Trafford. Jose Mourinho does not lose them to Arsene Wenger.
The Portuguese's sole defeat by the Frenchman came in the Community Shield.
Even during his awful autumn last year, his Chelsea side still beat Arsenal.
Mourinho has had an awkward start at Manchester United and is yet to record a league victory against top-six rivals.
He is deprived of players at both ends of the pitch, with striker Zlatan Ibrahimovic suspended and defenders Chris Smalling, Eric Bailly and Antonio Valencia injured.,
History, however, suggests Arsenal are his ideal opponents.
Factor in the Gunners' traditional problems in November, the month when they have the lowest points-per-game average, the fact that Wenger will be without the injured Hector Bellerin, and the probability that Alexis Sanchez's exertions for Chile mean the forward will be a substitute - and one narrative is taking shape.
Yet the alternative scenario is that Arsenal, as the form side, extend their unbeaten run to 17 games, exploit the weaknesses in United's second-string defence and take three points from Old Trafford for the first time since 2006.
If so, they would be nine ahead of United. Even at this early stage, that gap would be difficult to close.
But while it is undeniable Arsenal come into the game in better shape, they also have much to prove.
The past means they are rarely afforded the benefit of the doubt in major matches.
A lopsided fixture list means that, while they have faced three title contenders, all have been at home. The biggest scalp they have claimed on their travels is Watford.
These are two teams who have to make a statement. Arsenal's need is exacerbated by their last trip to Old Trafford, another day when United were short of strikers and suffered from defensive injuries.
The Gunners were shambolically bad when beaten 3-2 in February in a result that, perhaps more than any other, cost them the title then.
It was Marcus Rashford's league debut and he scored twice. Now Ibrahimovic's one-match ban could return the teenager to United's forward line. The other option is Wayne Rooney, whose only league goals in nine months came against Bournemouth.
But, while United dominated against Swansea 13 days ago, it was with a slow side and given Arsenal's speed, Mourinho has to provide an injection of pace.
It means Michael Carrick, whose six starts have all brought wins and who combined well with Paul Pogba in Wales, may drop out again.
Certainly the Portuguese has decisions to make. He has usually excelled in finding a physically strong, defensively sound team who can implement a counter-attacking blueprint to beat Arsenal.
He is still searching for that perfect formula at United.
MAN UNITED V ARSENAL
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