"Soldier Girls," which opened yesterday for a brief engagement at the Inner Circle, takes a curiously droll look at the failure of two misguided girls to get through Army basic training.

It was probably inevitable that the documentary filmmaking team of Joan Churchill and Nicholas Broomfield, observing female recruits, would end up focusing on a misfit, Joann Johnson, whose inability to repress a telltale smirk repeatedly provokes the wrath of her drill instructor, Sgt. Abing.

Johnson and Abing impressed the inquiring filmmakers as irresistible screen personalities right from the start. "As each recruit came in," Churchill recalled, "she was interviewed by the sergeants. From the beginning Johnson was saying that she'd made a terrible mistake. Sgt. Abing was there, and he was just a natural. We knew from those people alone there was interesting material. After all, one has to cast one's films, even in documentary."

Passing through town earlier this week, Churchill acknowledged that she and Broomfield were loath to approach the subject of women in uniform seriously. Having collaborated on a string of documentaries dealing with aspects of criminal justice (the most notable was the award-winning "Tattooed Tears"), they "were fed up with heavy films," Churchill said, "and wanted to have a good time on our next project. We began thinking of 'Soldier Girls' after seeing some postcards of girls at Ft. Jackson, Ga., in bayonet practice. There was something so incongruous about it."

The good time had by Churchill and Broomfield probably can be shared by spectators cordial to the idea of a documentary variation on "Private Benjamin." At the same time, it's more likely to confirm prejudices at opposite ends of the opinion spectrum than contribute to a useful debate.

"Keep smiling, Johnson," goes Sgt. Abing's indignant refrain. "Every time I see that smart-ass little smile, I'm gonna make a personal effort to wipe it off." He's as good as his word, but since Johnson is determined to drop out, his efforts end up as an exercise in slow-burning futility. What's more, she's not even the most incorrigible case in the platoon. That undesirable distinction eventually goes to a fellow recruit named Clara Alves.

The fact that Sgt. Abing is white and Pvt. Johnson black has inspired some reviewers to jump to the conclusion that Abing is being exposed as a racist when he chews her out. This interpretation is obviously contradicted by his equal dissatisfaction with Pvt. Alves, who happens to be white, and by the unanimous suspicion and irritation both girls arouse in NCOs, male or female, white or black. The filmmakers' attachment to an insubordinate kid like Johnson doesn't preclude respect for Abing the disciplinarian, in part because he appeals to them as an individual and a misfit himself.

One wouldn't expect the Army to be greatly amused by "Soldier Girls," at least on an official basis, so it comes as no surprise to learn that it's dismissed as "an extremely distorted account . . . obviously edited more for artistic and dramatic effect than to present an accurate portrait of basic training" in a statement drafted at the Training and Doctrine Command. A specific complaint that the movie "ignores the fact that the vast majority of enlistees completes basic training and serves competently" appears to have some merit. Churchill recalls 20 of the 50 girls in the platoon washing out of basic, a rate of attrition roughly 25 percent higher than the figure for all women recruits in 1980 and 1981, according to Army statistics.

Not that the filmmakers haven't tried for a certain balance, racial as well as attitudinal. Two recruits who make it through, Tuten and Hall, also are black and white, respectively, and Hall appears highly motivated. Nevertheless, the dropouts loom much larger in the scheme of things. Naturally, a film made for the Army would have been obliged to disregard the likes of Johnson and Alves. ("Soldier Girls," incidentally, was subsidized to a considerable extent by a grant from the Corporation for Public Broadcasting, and it's scheduled for a premiere telecast over PBS stations sometime next month.)

Every so often one suspects that the camera's presence may have emboldened the malcontents and led them to believe they would be safe as long as there was a film crew on the scene. However, it's unlikely that even an obtrusive camera could distort what appears to be a basically antagonistic human chemistry. Abing and the other NCOs surely would be just as provoked by Johnson and Alves if the filmmakers weren't present.