ANOTHER day, another turn on the managerial merry go round. Speaking from Japan yesterday, Arsene Wenger finally named the date on which he will assume the manager's chair at Arsenal. In turn, Stewart Houston left Highbury to become the 19th manager of Queens Park Rangers since the second World War.

Nothing too complicated there. Just cause and effect, action and reaction, leaving two sets of supporters in a pleasant, if temporary, state of raised expectations. Up in Scotland, however, yesterday's portion of plot was far less straightforward.

Iain Munro, until recently manager of Hamilton Academicals, took over at Raith Rovers less than a week after accepting the managership at St Mirren, which he relinquished in the aftermath of what is officially described as a "rethink". He will be Raith's fourth manager this year - their third, indeed, in a fortnight, since his immediate predecessor, Tommy McLean, high tailed it to Dundee United after just one week in charge, and a "rethink" of his own. It was described as a "shock departure

Come off it. There are no "shock departures" in football management. As Howard Wilkinson has pointed out, there are only two types of manager: those who have been sacked already, and those who will be sacked in the future. The imponderable factor is whether the time between appointment and departure can be filled with something to boast about before the inevitable happens.

"You don't get too surprised any more, Terry Venables responded last week when I asked him for his reaction, as a fellow professional, to the departures of Wilkinson from Leeds United and Ray Wilkins from Queens Park Rangers.

It depends on what you feel about the individuals. I was very surprised and upset for Ray because I think he'd handled it all exceptionally well, going down and sticking in there and keeping playing. He did seem to have this resolute attitude to keeping playing. I don't quite understand that.

"Wilkinson? He had a very good time at Leeds but he had a lot of disappointing results. All you know is the facts, and the facts are that they'd gone. Whether they'll be improved by the next guy remains to be seen.

Venables readily lent his support to the view that we are heading for an era in which the men formerly known as managers will be called coaches, with very specific responsibilities for the playing side of the club, leaving the business side of things to a general manager.

This is, after all, the title he was given when he took charge of England, and although the decision may have reflected the Football Association's view of his personal standing rather than its general policy, it has been retained by Glenn Hoddle, his successor, and has received approval as part of English football's efforts to absorb lessons from the rest of Europe.

One questionable side effect is a restriction on the coach's opportunity to make himself integral to the club. For the old type of manager, sustained success would lead to the founding of a dynasty. On the face of it, the new system would not encourage a Matt Busby or a Brian Clough.

At AC Milan, for instance, Fabio Capello had just won his fourth league title in five years when he left for Real Madrid at the end of last season after a series of disagreements with the general manager, Adriano Galliano. Now that a new coach, Oscar Tabarez, has made a terrible start to the season, it will be interesting to see whether he or Galliano, who has Silvio Berlusconi's ear, is still there this time next year.

There are exceptions to the new, short term mindset. At Auxerre, the current French champions, Guy Roux has held the reins for an astonishing 30 years. "I can't see that happening in Italy or England," Venables observed. "In Holland or France, maybe. But the demands of success here are too high."

Yet nowhere are those demands higher than at Old Trafford, where Alex Ferguson was given six years to establish himself before the off the cuff purchase of Eric Cantona added the final piece to his jigsaw. inaugurating the present era of success and awesome prosperity.

Ferguson had spent those years painstakingly rebuilding the club's foundations in the old fashioned way. Would a mere "coach" be granted such leeway?