|Manager and GM Paul Richards|
Buck would be the first person to occupy this position since Paul Richards who was the Orioles GM and manager from 1955 to 1958 when Lee MacPhail took over the GM role, leaving Richards as only the manager of the team. Even back in the 50s this was considered a unique situation. There are just too many reasons for this not to be a good idea and it is why few have ever tried to do it. The following is a list of individuals who I have found who have recently occupied both positions since 1980.
1981-1982 St. Louis Cardinals
In the beginning of the 1980 season, Herzog took over as manager from Bobby Winkles. In August, Herzog left the dugout to go to the front office as General Manager. He assigned Red Schoendeist to take the helm. However, during the offseason, Herzog felt that no one could manage better than he could, deciding to occupy both GM and manager positions. In 1981, Herzog had the most wins in the NL East, but failed to win the division due to funky strike-shortened season rules. In 1982, the Cardinals downed the Brewers in the World Series. Herzog is one of the few (maybe only) person to win a World Series as both manager and General Manager in the same season. It should be noted though that he did resign from his GM duties in April of 1982, so it may not be wholly accurate to refer to him as holding both titles for a championship team.
1981 New York Yankees
The Yankees of the 70s and 80s were a dysfunctional mess. This became readily apparent during the merry go round of coaching that Michael oversaw during his tenure as GM. He performed poorly and Bob Lemon took over and took the Yankees to the World Series. The Yankees lost and Michael was no longer the GM.
1983 Philadelphia Phillies
Paul Owens thought the Phillies were underperforming and that he could bring more out of the team. He helped them finished 47-30 and took them to the World Series where Rick Dempsey and the Orioles were waiting for him. Encouraged by his performance as manager, he resigned from his front office position to dedicate himself to the dugout. He finished the year 81-81 and was removed as manager. From 1985 until his death, he was assigned as a senior adviser to the Phillies.
1988-1990 San Diego Padres
Year two of the Larry Bowa tenure went just as poorly as the first and McKeon brought down the ax. He decided to take the reins himself and the team went 67-48 over the rest of the season, finishing in third place. McKeon retained both titles in 1989 and the Padres went 89-73, second in the NL West. 1990 though was not as successful and McKeon resigned as manager after going 37-43. After the season, he also had his GM duties taken away.
1990 Atlanta Braves
Bobby Cox oversaw several poor Atlanta Braves teams managed by Chuck Tanner and Russ Nixon. As a fairly successful manager with the Toronto Blue Jays, it made sense for Cox to be rather critical of how the managers under him performed. Cox decided to take matters into his own hands 66 games into 1990. His presence did not remarkably improve the team's performance in 1990, but he felt he could do more to help the young players he had been accumulating of the past five years in the dugout as opposed to in the front office. After the season, John Schuerholtz was lured from the Kansas City Royals to serve as the Braves GM with Bobby Cox remaining in the dugout.
I think it says a lot that 1990 was the last time a manager doubled as a GM. Whitey Herzog and Jack McKeon were the only two who have ever done this over a whole season in the past 32 years. They were both successful, but found it to be overwhelming and thought it best to concentrate on one position. To me, it is inconceivable that one person could do both jobs adequately. If Angelos does allow Buck to serve in both roles and Buck chooses that route, I do not think this team will be best served under that scenario.