Like all enduring rivals, Sir Alex Ferguson and Kenny Dalglish have more in common than they care to admit. They share a Glaswegian heritage, a faith in family and fealty. Each is a polarising personality capable of sustained warmth and sudden, shuddering coldness.
Fate has thrown them together again as directors of clubs they shaped and imbued with their spirit. Their roles at Manchester United and Liverpool respectively may be largely ceremonial, and their avowed lack of ambition must be acknowledged, but they remain too close to the seat of power for their presence to be uncomplicated.
Each has the capacity to continue to dominate by proxy. They are not distant figures enveloped by the mists of legend. They are part of the fixtures and fittings. As board members, albeit with an ambas-sadorial brief, their influence remains tangible.
Though their managerial successors, David Moyes and Brendan Rodgers, are apparently comfortable with the dynamics of the situation, they will naturally be judged against men deemed to embody their club's eminence. Any public utterance by Ferguson and Dalglish will be finessed to suit the prejudices of their critics.
Ferguson is still The Man at Man U. The emotions generated by Dalglish's return to Liverpool, announced on Friday night, 17 months after he was sacked from his second stint as manager, proved his status as a cultural icon has not been neutralised by nostalgia.
Moyes has the most immediate problem. It is one thing to live with reminders of Ferguson's splendour, the statue and the stand which bears his name. It is entirely another to have to deal with the contemporary consequences of his actions.
The intricacies of regime change at Old Trafford are already being ignored because of the infantilism of a football culture which relishes scorn and rancour. The difficulties of transition, daunting because of United's size and complexity, have been compounded by constant comparisons.
Ferguson's midweek interview on US television, mesmerising in its tone and detail, presages the media blitz which will accompany the publication of his second autobiography later this month. No one can doubt Ferguson's work ethic, despite his eye-watering £2 million advance.
Promotional appearances in Manchester, Glasgow, London, Aberdeen and Dublin will doubtless be nuanced and offer a fascinating insight into the principles of leadership. Yet the headlines will inevitably be dominated by such scraps as perceived side-swipes at Wayne Rooney.
There is no malice in Ferguson's exploitation of a stellar profile, and he has the right to be true to himself, yet he has failed Moyes because he has inadequately protected him from becoming a prisoner of his own reputation. Moyes is not a Wilf McGuinness, nor a Frank O'Farrell, but he cannot compete with 49 trophies. No manager can. His inheritance is an unbalanced, ageing squad which has lost the momentum supplied by hunger and fear.
Ferguson is not solely liable for the paucity of the legacy, though his sustained support of the Glazers, whose takeover has cost United £680m in interest, fees, bank charges and debt repayments, is a puzzling challenge to his principles.
Moyes is still adapting to the fiscal and political intricacies of United as a plc registered in the tax haven of the Cayman Islands and floated on the New York Stock Exchange. Rodgers bears responsibility for the investment strategy of the Boston-based Fenway Sports Group.
Many suspect platitudes disguise commercial intent. Liverpool's owners surely know Dalglish's character is unsuited to a sinecure. His voice will be heard. Opposition will coalesce around him if Rodgers regresses, whether he likes it or not.
Football is a people business. Dalglish's reacceptance draws a line under an unpleasant case of fratricide and suggests Liverpool have learned the lessons of the isolation endured by Bill Shankly before his death. Ferguson is in danger of emulating the destabilisation wrought by Sir Matt Busby.
Whoever said "Never go back" might have been on to something.
Arrest the real agents of prejudice
Anti-Semitism is a complex, sensitive and socially significant issue. It is not a subject for soundbites and grandstanding, but such superficialities are shaping the debate.
The Met Police have chosen to announce that Tottenham and West Ham fans face arrest if they use the "Y" word during today's derby at White Hart Lane.
Taken at face value, they will struggle to match perceptions of their duty. The FA's well-intentioned efforts have backfired in encouraging Spurs fans to chant the word with increased intensity as an expression of identity.
What are the police to do? Haul out token offenders, or arrest 5,000 fans at a time? Far better, surely, to concentrate on the real threat to public order represented by the abuse from a minority of West Ham fans in last season's fixture.
Anyone who hisses to imitate Holocaust gas chambers and chants about Adolf Hitler has no place in a civilised society. Should they ignore the entreaties of West Ham's manager, Sam Allardyce, to desist, they are a legitimate target.
Those of us not of the Jewish faith should tread carefully here, but a sense of proportion is needed, now.
David Beckham, bless him, has started something. His posing pouch, projected on to the side of big buildings, has spawned a series of imitators. Cristiano Ronaldo is threatening to launch a CR7 Boys underwear collection. Didier Drogba has designed a range of undergarments with "a positive social impact". Pants by name, and nature.