You wouldn't ask Steve Redgrave to play at centre forward for England.
Still less would you expect Michael Owen to win an Olympic gold medal for rowing. So who in their right mind would ask a media man to run an advertising agency?
Last week, B-Com3's chief executive, Roger Haupt, did just that. He shocked the industry by promoting Bob Brennan, the Starcom MediaVest chief operating officer with a well-earned reputation as a ferocious media operator, to the position of president of Leo Burnett Worldwide.
'Roger has let a big hairy fox into the chicken coop and feathers are going to fly,' were the words of one astonished onlooker.
But it seems that the industry is just going to have to get used to it.
More and more people are transferring their skills between different disciplines in the advertising and media worlds.
In the same B-Com3 reshuffle, Haupt appointed John Farrell, who used to run D'Arcy's direct marketing division IMP, as the president and chief executive of D'Arcy Worldwide.
In London, Stevie Spring left Young & Rubicam to become the chief executive of the More Group. David Wheldon and Richard Burdett, the chief executive and vice-chairman of CIA respectively, have both done stints at ad agencies and at client companies.
And Nick Brien, the chief executive of Leo Burnett, enjoyed a distinguished career in media before taking on his current role.
Why is this happening? And why is it happening at more and more elevated levels? Haupt is clear about the reasons for his choice. 'I'll go for the best athlete every time. Bob just happens to be in media,' he says.
Brennan is confident that he is the best man for the job. 'My media background is incidental,' he argues. 'I was chosen for my leadership skills. I have proved that I can drive change.'
Which suggests that there just aren't enough such people to go round.
An advertising agency is bound to look among its own kind before casting the net beyond the creative world. However, all the big international networks are struggling to find proven leaders to drive them forwards at a challenging time for the industry.
But the people in question prefer to see the phenomenon in a more positive light. 'The role of the medium in delivering the message is becoming ever more important, so my experience is of added value to Leo Burnett,' Brennan says. 'Media is an essential part of creative success.'
The death of the full-service agency is in danger of triggering a blinkered, narrow focus on either creative or media, which would ultimately threaten clients' interests. Unless, of course, specialists are willing to cross the divide.
Farrell is convinced that his alternative background will mean that he is able to serve D'Arcy better. 'Clients want ideas that work across every discipline; they want brand strategies, not just advertising strategies,' he says.
Individuals seem to profit from developing a wider skill base. Brien was given the chance to broaden his experience in a more gradual way than Brennan will be able to. Brien was made the deputy managing director of Leo Burnett while continuing as the European media director, so he would be able to cut his teeth on advertising and prove himself before taking the final plunge.
That all seems very nicely managed by Burnetts. But could it be that some of these discipline-hopping executives are simply opportunists, creating a unique selling point in order to advance their personal careers?
Burdett - who worked at Saatchi & Saatchi for 11 years and at Flextech for four years before moving to CIA - freely admits that his career has been a series of fortuitous accidents. As he puts it: 'The 'job for life' does not exist, and my generation wouldn't be interested even if it did. The whole structure of work and careers is changing, and that makes versatility valuable.'
Burdett was not in the least surprised to hear about Brennan's new appointment.
'People are, increasingly, looking for multi-skilled managers,' he claims. 'Agencies are in danger of being alienated from what clients need on a day-to-day basis.'
Spring -who has also been a lawyer and a client - maintains that at a senior level the difference between managing a media owner and an advertising agency is virtually non-existent. 'You are still managing a people-based business that works on intelligence and creativity,' she says. But she also concedes that 'companies are always looking for fresh insight and a different angle'.
It wasn't always this way. There was a time when an advertising agency person would not dream of dirtying his or her hands by taking a job in the media. And, until recently, no media johnny could have found themselves accepted in an advertising agency.
Brennan agrees: 'There was a point when media was relatively unimportant in terms of marketing success. Twenty years ago, 90 per cent of success was a great creative message and 10 per cent was media. Today, it's more like 50-50.
'Media specialists had to become great thinkers, and a new breed of media professionals has grown up as a result. But most of the industry is still struggling with that.' In response to this snobbery, he is keen to emphasise the close working relationship he has enjoyed with Leo Burnett's creative bosses for many years.
Brien also acknowledges that he felt the need to prove himself to the advertising agency. 'I had to be like a sponge,' he says. 'I went to shoots and spent time working through all the departments so that I understood the creative and planning processes. But I never left media behind. You don't stop thinking about it.'
In the present climate, it seems that the more all-round thinking you have to offer, the better your chance of success.