If Manchester United's board are to choose between Pep Guardiola or Jose Mourinho as Sir Alex Ferguson's successor, they will be ignoring everything that convinced their predecessors about the Scot 25 years ago.
United will break with tradition by going with Guardiola or Mourinho, choosing a continental manager for the first time. But it's how both men have built their reputations that must be questioned inside the United boardroom.
Where stability has become a mantra under Ferguson, can the same be guaranteed should Guardiola or Mourinho be his replacement?
Before United, Ferguson spent eight years at Aberdeen, dismantling, building and then rebuilding successful Dons teams. Winning the league and the European Cup Winners' Cup are now folklore at Pittodrie, but it's the way Ferguson sustained success, regenerating his squad, that gave the likes of Sir Bobby Charlton and former chairman Martin Edwards the confidence to back the Scot when fans were calling for his head in those early years.
Would the current board feel the same supporting Guardiola or Mourinho?
Mourinho will bring glory to United, there's little question of that, perhaps even another Champions League trophy. But as he's bounced from club to club, the Real Madrid coach has never stuck around long enough to prove himself capable of regenerating a successful team. Indeed, outside of Chelsea, the opposite is the case, where Inter Milan and Porto have struggled to recover as Mourinho moved on. He left Inter only two years ago, having guided the Nerazzurri to a historic treble, yet they have since been through four coaches and are playing in the Europa League this season.
The failure to plan beyond his own reign is in stark contrast to Ferguson, who has spent the past 18 months openly discussing the building blocks he's put in place so his successor won't be left with an ageing, deteriorating squad.
For Guardiola, evidence of what United can expect is even thinner on the ground. The obvious questions are how would he have handled a Barcelona without Lionel Messi, Xavi and Andres Iniesta? Could another club, even the size of United, survive Guardiola's outlandish transfer market failures? From Zlatan Ibrahimovic and Keirrison through to Dmytro Chygrynskiy and Martin Caceres?
As for regenerating a squad, Guardiola hasn't been in the coaching game long enough for anyone to successfully predict how he would do. A concern for United directors is the claims inside Barcelona that Guardiola wanted to rip up the squad that Tito Vilanova now has 11 points clear of Real Madrid. Guardiola, it's reported, wanted rid of Cesc Fabregas, David Villa and Alexis Sanchez, along with Gerard Pique, who he fell out with during the season.
The global profile of both men and their record of immediate success will be attractive to United. But for those burdened with the responsibility of getting right the choice of Ferguson's successor, there will be nagging doubts about whether Mourinho or Guardiola can offer the stability and longevity that United's success has been built upon.
He won't get the marketing men excited and perhaps some in the Glazer household may not have even heard of him. But David Moyes ticks many of the boxes that will remain unchecked when United are discussing Mourinho and Guardiola.
Still not 50, the Everton manager has been at the helm for ten years and is now in the middle of building his third team at Goodison Park - one he rates as the best he's had during his decade on Merseyside.
Moyes' approach to development is in the Ferguson mould. Just a glance at the present setup at Finch Farm is enough to suggest he would fit seamlessly into the culture at Old Trafford.
Bringing through the likes of Jack Rodwell and Ross Barkley, signing and developing the talent of Marouane Fellaini and Nikica Jelavic, along with putting down and maintaining experienced foundations like Phil Neville and Leon Osman are all the hallmarks of what Ferguson has done at United - only to a much more limited budget.
Unlike Mourinho, Moyes gets along with his board and chairman Bill Kenwright - and it can be argued has a much better track record of buying and developing young talent than Guardiola.
Even on the personality scale, if Moyes was ever to move to a Champions League club, he would surprise many cynics with his humour and charm. With Everton not enjoying the profile of bigger rivals, Moyes' engaging personality has been largely a well kept secret on Merseyside. He doesn't go out of his way to court the media, but exposed to a bigger, global audience, Moyes wouldn't find himself out of place.
But what he lacks, in contrast to Mourinho and Guardiola, is experience in European football.
And this is the dilemma for United, or any top four aspirant when considering Moyes. Is he the real thing, who just needs an opportunity? Or a good, solid Premier League manager whose found his level?
Mourinho, Guardiola or Moyes ... they all have their pros and cons. The decision for United's current custodians is what they value most in a manager.