The Republican National Committee has dispatched one of its top political organizers to Virginia to prop up the gubernatorial campaign of State Attorney General J. Marshall Coleman, which some GOP strategists say is faltering and in disarray.

Fearful that a Coleman defeat would be seen as a repudiation of the Reagan administration, the GOP is sending Kenneth Kling, a Northern Virginian who played key roles in the victories of Gov. John N. Dalton and Sen. John W. Warner, to Richmond. Kling is expected to coordinate a special effort apart from the Coleman campaign.

National party leaders made the decision after polls showed Coleman trailing the Democratic candidate, Lt. Gov. Charles S. Robb, and complaints that a Coleman defeat, after 12 years of GOP victories in Virginia, would have national repercussions.

Coleman and his top advisers insisted yesterday that the campaign is, in the phrase of campaign manager C. Anson Franklin, "on course," but more than half a dozen GOP professionals interviewed last week expressed varying degrees of concern.

"The campaign is in a shambles," said one RNC official, who, like the others, would not permit his name to be used.

"It's not panic, not yet," added another Republican associated with the Virginia campaign. "But the campaign has not been effective in clearly identifying differneces between Coleman and Robb on state issues."

Coleman has successfully exploited his ties to the president, the veteran party leader said, adding: Virginians want a governor who talks about roads, water and other local problems, and Marshall is still muddy there."

Polls that show Coleman trailing Robb by five to 11 points prompted "grave and serious concerns about what those figures mean," said another strategist active in the GOP campaign.

A source at the RNC said the party is not anxious to have either the Virginia or New Jersey governors' races, the only statehouse races in the nation this year, interpreted as a vote against the president, but because Coleman has made Reagan a cornerstone of his campaign, the national party has little choice but to jump in.

What Kling, a special assistant to Transportation Secretary Drew Lewis until his resignation Friday, will do in Richmond is not clearly defined. His duties are expected to include deciding how the RNC can best spend $150,000 to $200,000 it has earmarked for a separate advertising campaign in Coleman's behalf.

One Coleman supporter said he hopes Kling will "divert the Coleman campaign from the mind-set that it knows the state so well, and the issues so well. It is adhering religiously to a game plan that is not producing."

Another professional Republican campaign consultant said "there is some concern about the out-of-state management" of the campaign, specifying media consultant Douglas Bailey and political director Matt Wirgeau.

Wirgeau, who was a Midwest coordinator for Reagan last year, reacted sharply to Kling's assignment, saying Kling's role within the Coleman organization will be "none, absolutely none. I don't need help," Wirgeau said. "By every measurement, our organization is good."

Wirgeau described Kling as "my very good friend [who is a] campaign junkie who just can't stand to miss a race. Kenny must have gotten bored in Drew's office."

Franklin concurred that Kling "is not coming to work for us," but he added: "We have sought his advice on a number of occasions and we value his judgment and abilities very much. And we have talked to the national committee about assistance in a variety of ways, including financial."

Another consultant said "there has been a lot of griping" about the media campaign designed for Coleman by Bailey. "His whole campaign is based on selling a candidate who is poor, whose dad died when he was 9 and who likes Ronald Reagan more than you do."

Some of Coleman's problems stem from what he and his top advisers call "a couple of bad breaks" involving conflict-of-interest allegations against Nathan H. Miller, his running mate for lieutenant governor, and William B. Wrench, a member of Coleman's finance committee, who resigned from the state highway commission.

Matt Wirgeau, Coleman's political director, concedes that the Robb campaign "has had a couple good weeks." But he said, "by every measurement, [the Coleman campaign] is in good shape."

Campaign manager Franklin pointed to a Norfolk newspaper poll, released today, in which Coleman trails Robb by five points, as an indication of a trend toward the GOP nominee. Last Sunday a Washington Post poll showed Coleman trailing by 11, and a Richmond Times-Dispatch survey had him behind by nine.

One of the first indications that a campaign is in trouble, noted one strategist, is "when the money stops coming in." The first public accounting is due tomorrow, and both campaigns are expected to report contributions in the range of $1.5 million.

On the stump last week, Coleman appeared confident, and oblivious to his critics. He concentrated on pointing up his differences with Robb.