In the event, those achievements mattered not. This dismissal is about personalities and procedure, not performance. Its roots predate Rioch's arrival, being based in the murky relationship between George Graham, Rioch's predecessor, and Rune Hauge, the Norwegian agent. The skulduggery which brought Graham down meant that Rioch took over a job with very different parameters to any of his English counterparts. Transfer negotiations were conducted by the board, not by the manager.
Given the circumstances of Graham's dismissal this was unavoidable, but it does not appear to have worked. Many names were linked with Highbury, but after the initial arrival of Dennis Bergkamp and David Platt, none arrived. Even those two appeared to be overpriced; Platt has been a disappointment while last week Ken Bates, the Chelsea chairman, was quoted as saying he had been offered Bergkamp for more than pounds 2m less than Arsenal paid.
Since then quite a team has been assembled on the back pages of the tabloids - Frank de Boer, Graeme Le Saux, Robert Jarni, Alan Stubbs, Bixente Lizarazu, Jason McAteer, Paul Ince, John Moncur, Lee Bowyer, Tim Sherwood, Gary McAllister, Lee Sharpe, Zinedane Zidane, Christophe Dugarry, Les Ferdinand, Roberto Mancini, Attilio Lombardo, Jurgen Klinsmann and, last week, George Weah.
Even if half of these are unfounded speculation, it is still quite a list - everyone except a goalkeeper. However, the only player actually signed was a reserve goalkeeper, John Lukic, on a free transfer from Leeds.
McAllister was offered to Rioch, and rejected, possibly on the grounds of age. Many of the rest were lost in the system, somewhere between Rioch asking the board to try and buy them and the board securing the deal. Rioch occasionally hinted at his unhappiness with the system and matters were not helped by an clash of personalities with David Dein, the Arsenal vice-chairman and the main power at the club.
Dein and Rioch are very different people. Rioch is a believer in moral absolutes, a stern disciplinarian whose code is strongly influenced by his upbringing in a military family. Dein is a smoother figure, a businessman, football politician and socialite. Even under George Graham there were problems over Dein's habit of cultivating friendships with players.
Rioch's own relationship with his players was chequered. He was a great support to Paul Merson as he continued his comeback from alcohol and gambling addiction, but had a difficult time with Ian Wright.
Problems simmered between the pair from the start and they came to a head in a blazing dressing-room row after Arsenal's FA Cup third-round defeat by Sheffield United. Wright later handed in a transfer request, which the board turned down on Rioch's advice. Wright has recently published his account of the period in a new autobiography.
One of the problems between them was that Arsenal under Graham had become over-dependent on Wright's ability to snaffle goals from long-ball football. Rioch attempted to update that style, introducing short passing and making Bergkamp the focus of the team.
To an extent it worked - Arsenal were regularly more attractive than in Graham's later years. Attendances rose to an average 37,568, the third best in the country. But too many players were being asked to change old habits and, too often, the team fell between styles.
Arsenal had begun better than expected, despite waiting seven games for Bergkamp to score. For a while they looked as if they might be contenders, defeating Manchester United and being in the first three in December. But the old failing, a lack of midfield creativity, handicapped the side. Then both Tony Adams and Steve Bould, for years the defensive bedrock, suffered serious injury. Platt, too, was rarely fully fit.
February's Coca-Cola Cup defeat by Aston Villa ended dreams of glory, although two late goals - from Platt and Bergkamp - secured a European place in the final game.
The opponents that day were Bolton, the club Rioch had forsaken to go to Highbury. Although he had left Bolton, Bolton never quite left Rioch - his habit of holding Bolton's more limited players up as examples to Arsenal's self- confident stars was not one to endear him to the likes of Wright. Neither could he recreate Bolton's family atmosphere, despite encouraging players to mix socially.
In the wake of his departure, some Arsenal fans have suggested Rioch was not "big enough" for Arsenal, that perhaps a club like Bolton is his level. Yet he won twice as many Scotland caps as Graham, captaining them in a World Cup and winning a championship medal with Derby. Wimbledon have shown that even in the capital it is possible to build a family atmosphere if the players are willing. Maybe Rioch took too long to discover which Arsenal players would not adapt. Or maybe not - he could hardly off-load them until he bought replacements. He was big enough for Arsenal, and hard enough, but he was not enough of a politician.
That is not something that could be said of one of the candidates for the vacancy, Johan Cruyff, who conducted a running battle with the equally strong-willed Barcelona board before finally being manoeuvred out last season. Terry Venables, now installed at Portsmouth, would not have taken kindly to interference from the board, not after his experiences at Tottenham. For Arsenal, it seems, the crisis may only just have started.
FROM ALDERSHOT TO ARSENAL
1947 Born 6 September in Aldershot to Scottish parents.
1963 Joins Luton as an apprentice.
1969 After 148 League games for Luton, moves to Aston Villa for pounds 110,000 with brother Neil.
1972 Scotland manager Tommy Docherty names Rioch in his squad, but he pulls out to play for Villa. Docherty later says he would no longer consider him. Rioch says he will aim to play for England as he has dual qualification.
1973 Gives up Villa captaincy in May after his fourth cartilage operation.
1974 Joins Derby and wins championship in his first season.
1975 New Scotland manager Willie Ormond calls him up for first of 24 caps.
1976 After 106 League games for Derby, joins Everton for pounds 180,000 and makes 30 appearances for them.
1977 Appointed Scotland captain by manager Ally MacLeod. Returns to Derby for another 40 games. Goes on loan to Birmingham and Sheffield United.
1978 Captains Scotland in World Cup in Argentina.
1980 Joins Seattle Sounders.
1982 Appointed Torquay player-manager.
1984 Resigns after kicking player Colin Anderson in a fit of temper during training.
1986 Appointed at Middlesbrough - steers them clear of relegation.
1987 Guides 'Boro to promotion from Third Division.
1988 Leads 'Boro back into First Division.
1990 Loses job just days before Middlesbrough appear in their first final - the Zenith Data Systems - in 102 years. Becomes Millwall manager.
1992 Leaves The Den to take over from Phil Neal as Bolton manager.
1993 Wins promotion to First Division and guides Bolton to FA Cup triumphs over Liverpool and Wolves.
1994 Takes Bolton into FA Cup quarter-finals with victories over Everton, Arsenal and Aston Villa before losing to Oldham.
1995 Takes Bolton to Coca-Cola Cup final, where they lose 2-1 to Liverpool, but gains consolation with promotion to the Premiership, via 4-3 play- off final victory over Reading at Wembley. Offered a three-year contract which he only recently signed.
1996 Sacked by Arsenal.
1894-97 Sam Hollis
1897-98 Tom Mitchell
1898-99 George Elcoat
1899-04 Harry Bradshaw
1904-08 Phil Kelso
1908-15 George Morrell
1919-25 Leslie Knighton
1925-34 Herbert Chapman
1934-47 George Allison
1957-56 Tom Whittaker
1956-58 Jack Crayston
1958-62 George Swindin
1962-66 Billy Wright
1966-76 Bertie Mee
1976-83 Terry Neill
1983-86 Don Howe
1986-95 George Graham
1995-96 Bruce Rioch