When Marion Barry becomes mayor of Washington on Jan. 2, most of the top leadership in his government -at least in the beginning-will be the same people Barry described during his election campaign as "bumbling and bungling" in Mayor Walter E. Washington's administration.

Throughout his underdog quest for the mayor's office, Barry listed the alleged incompetent department heads in city government. He said if elected he would change two-thirds of the leadership of the city's bureaucracy-even if it meant making head-on challenges to tough civil service regulations.

Now, after nearly two months of ehaustive study of the city government, an aborted attempt t alter civil service guidelines and a surprising awakening to the pervasive crisis-control nature of D.C. government, Barry and his advisers have come to feel that it will be four or five months before they can "take control" of the city bureaucracy.

In sharp contrast to his aggressive campaign and at times almost cavalier attitude as a candidated, Barry's transition has become a plodding, deliverate, closed, and at times almost textbook operation. Its lofty ideals and "superstar" goals for new department heads have become the butt of good-natured private chuckles by som political observers, city department heads and even Mayor Washington, who watch with interest as the young, soon-to-be administration comes to grips with the apparently more limited realities of city leadership.

Policy initiatives have been put on the back burner. Rival interest groups play tug-of-war over jobs. Task forces report hundres of looming, crises that will turn the first weeks of the new administration into a virtual fire-extinguishing operation rather than a flood-tide of new direction.

Even the vaunted "first four" top appointments designed to reflect the "competent and compassionate" character of the Barry administration-city adminstrator, housing director, budget director and corporation counsel-may not be on the job until mid-February, said Ivanhoe Donaldson, Barry's longtime friend and principal adviser.

"We've been overwhelmed," Donaldson, slouched in a chair behind his desk at the Barry transition office in the National Theater Building, said last week. "We're working with a minimal group of professional [staff] and trying in two months to evaluate a billion dollar government." Delano E. Lewis, the C&P Telephone Co. executive who directs the 15-member steering committee, tow dozen staff persons (mostly volunteers) and 1,500-member task forces which make up the Barry transition effort, agreed.

"We've been consumed with trying to get a handle on taking over. It's a big job," Lewis said. "You finally say to yourself that you just can't tackle quickly as you can without making mistakes."

Barry, at serveral points angered by press disclosures of persons under consideration for top appointments, has been extremely secretive about the names of persons under consideration.

Three of his most loyal aides-Donaldson, his longtime friend; Lewis, the transition chief, and James O. Gibson, a planner and businessman who is also a trusted friend of the mayor-elect-have worked most closely with the selection of new appointees.

As of last week, about two dozen people had been interviewed for six jobs, Donaldson said.

Barry said during a press conference Friday that he has Selected persons to fill two of the four posts and also chosen about "80 percent" of the people for his 34-position personal office satff, (About 20 of those people, middle-and lower-levels workers, will apparently be holdovers from the Washington administration.)

As in the past, however, Barry refused to name any of those selected or interviewed, saying, "It's a delicate situation."

The embryonic administration has promised to bring what it considers top-caliber department heads to city government, and hopes that the announcement of such selections will help establish the character of the Barry government.

Some of the proposed candidates-like a list of possible choices for corporation counsel that included two Superior Court judges, high-level federal government sttorneys and well-paid partners in premier city law firms-have been sloughed off as unrealistic by some city professionals.

"Lawyers thought it was a pretty good list," one transition team member said privately. "But they were smiling, too, knowing that they (the administration) weren't getting any of those people. Everybody was happy to see them looking like that, but they know he's gonna have a helluva time getting those kind of people to go on board." Donaldson and Lewis said they disgree.

Last week, Barry was quoted in a story in The Post as telling an audience at New York Avenue Presbyterian Church that the city's bad reputation was hampering his recruiting drive.

On Friday, however, after some confidants privately became uneasy with those remarks, Barry said the statement had been taken out of context. The city's reputation was not a problem, he said. "I think I have been fairly successful with attracting and interviewing some top-flight people," Barry said. "I'm batting 800."

Barry struck out, however, on his attempt to place new conditions of employment on the estimated 20 people on Washington's personal staff who will be retained in the Barry administration.

Two weeks ago, at the behest of the new administration, personnel director George R, Harrod informed the 20 that they would be kept in their present positions in the new administration only if they signed slips ostensibly giving Barry the right to remove them at will.

Washington, who said he was unaware of signings before they took place, directed Harrod to destroy the slips in the presence of the workers because in Washington's opinion they appeared to violate civil service regulations.

When asked about the aborted personnel manuever, Barry termed it "a misunderstanding," and maintained he could still transfer the workers freely.

Washington, who lost his reelection bid in a close primary contest with Barry and Sterling Tucker, has virtually bent over backward to assist the incoming administration, according to Barry transition team members.

Privately, however, Washington, who campaigned as an experienced pragmatist, seemed somewhat amused last week at the mellowing of Barry's tone and the mayor-elect's 11th-hour education to the unglamorous and unending tough decisions to be faced as the city's chief executive.

"I looked at their list of the things they have to do in the first month in office," Washington said. "In 60 days, it'll be a whole different list."

Washington also questioned Barry's decision earlier this month not to actively oppose legislation that would give the City Council confirmation authority over Barry appointees.

Washington said low salaries and civil service regulations in themselves would hamper Barry in atracting the kind of people he wanted for the administration. Confirmation, the mayor said, would create still a third deterrent.

Washington said he asked the incoming mayor if he wanted the legislation vetoed, and Barry said that decision was up to Washington. Washington choe to veto the bill, but the council overrode that veto at its Dec. 12 legislative session.

That night, Washington publicly chided the council for failing to show "compassionc for the new major by approving the confirmation provision.

Washington said he has repeatedly todl Barry that many of his positions as a candidate will have to be modified now that he is responsible for running the government, and not just criticizing its operations as a candidate or a councilman on the other end of the District Building's fifth floor.

Washington said he has warned Barry that the incoming mayor may soon face a political conflict because the mayor-to-be is advocating increased economic development to create more jobs, while many of Barry's strongest supporters are no-growth advocates.

"Marion keeps saying, 'I'm talking to them, I'm talking to them,' and I keep asking him, 'What are you telling them?'" Washington said. "He just says, 'I'm working on it. I'm working on it.'"