cgardner
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I've found that lighting problems are most easily solved by understanding human perception and then working backwards from the perceived perceptual goal, to strategies to achieve the goals, finally arriving at the decision of what tool will best implement the strategy.
Start with remembering that a photograph is an illusion of reality created in the brain of the viewer by matching patterns of contrasting tone, color and shapes to stored memories of real objects in various types of light. On the most basic level objects are perceived as being "natural" or not depending on whether the key light is above the object or not because most light sources in nature and most artificial lighting comes from above and creates downward shadow patterns.
It is the shadows which provide most of the clues regarding shape. I first realized this back in the mid-1970s when I was working making maps at National Geographic. One of my jobs involved shooting halftones and color separations from a relief plate of the mountain ranges a cartographic artist would draw by hand in pencil. I noticed that the only thing the artist was drawing were the shadows the mountain would cast in 45 degree lighting. The illusion that those shadows represented mountains of various heights was created by how long the shadow were. The brain sees the shadows and from their shape interprets the shape of the object. Realizing that makes it easier to understand why short lighting is so effective for portraits: it models the size and shape of the nose realistically.
Conventional wisdom says that soft lighting is created with large diffusers. But the illusion that the light is "hard" or "soft" is actually a more complex perceptual process in which the size, shape and texture of objects is discerned from: 1) the shape of the shadows the objects cast; 2) how dark the shadows are, and 3) how gradual the highlight/shadow transitions are -- in that order of priority. I learned this in a very practical way, shooting wedding candids with two single power Graflex bare strobes back in the early 1970s. I learned that even direct flash can be quite flattering if: 1) the shadows are well placed to model the face naturally with short lighting; 2) a second flash is used to open the shadows and reveal detail in them, and; 3) the fill is kept "neutral" over the camera lens so it falls off front to back and "pushes" the transitions of the key light back instead of crossing and canceling them.
So there are actually three different variables which can be manipulated to create a "hard" or "soft" look to the lighting.
1) The shape of the shadows is a function of the angle of the key light to the object.
2) How dark the shadows are is a function of the level of the fill.
3) How gradual the transitions are is a function of the "apparent size" of the modifer, how it is aimed, and the angle of the fill light.
So part of the solution to the dilemma of creating lighting which looks hard on the body and softer on the face would be arranging the pose so the key light is cross-lighting the body but at the same time the lighting on the face is relatively flat. Butterfly or loop (which is simply butterfly slightly off center) are good strategies for body builders. Consider the fact they spend hundreds of hours pumping iron to make both sides of their bodies the same: symmetry. So does it make much sense to light from the side with an asymmetrical lighting pattern? I don't think so. Butterfly is a crossed lighting pattern, it just crosses the body vertically not horizontally. So it will both define the 3D shape with natural looking downward shadows while at the same time creating a symmetrical lighting pattern.
Don't take the term "butterfly" too literally here. I use it generically to denote a key light centered with whatever you want to appear symmetrical. Usually in a portrait it would be centered on the nose, but in the context of shooting a body builder obliquely you'd want the light 45 degrees off axis centered on the center line of the torso and high enough to create a downward symmetrical shadow pattern. The steeper the angle the longer the shadows and the bigger the muscles will look perceptually. Then when the face is turned full to the camera it winds up 45 degrees from the key light: flattering short lighting.
All that stuff above involves lighting angle to define shape with the key light. If the light is well placed a direct light source would create better definition of the muscles than a diffuse one, without making the lighting look too harsh on the face -- if the second step is also well executed.
Making the lighting pattern defined by key light placement harder or softer is simply a matter of how much fill is added from the direction of the camera. As previously mentioned putting more fill on the face than body by feathering the fill upward off the body would be a way to do that. Since fill used near the camera doesn't create any shadows which are really noticed there is no compelling reason to put a huge modifier on the fill source.
Huge modifiers are a bit of a knee jerk reaction to the conventional wisdom that BIG = DIFFUSE but what actually creates diffuse shadows is the fact that light hits an object from many different directions with varying intensities. What happen when a key light is placed to the side but fill is placed over the camera? Light hits from two different, widely spaced directions. What happens when fill is moved off axis to the side opposite the key light? First it creates shadows of its own. If those shadows cross a key light shadow an unlit distracting void is created. Secondly the fill begins to cancel out the modeling and shadow transitions of the key light. The more the fill fights the key light like a head-on car crash, the shorter the shadow transitions of the key light becomes.
If shooting competitive poses with oiled bodies a bare bulb flash for fill would be quite effective. The reason the bodies are oiled is because the oil creates specular highlights which increase contrast and by doing so enhance the 3D effect of the lighting. That being the case the best choice for fill would be a specular source positioned over the camera where the specular reflections off the highest parts of the muscles would be reflected back into the camera.
If shape and shadow detail are controlled well with key and fill light placement the size and character of the key light modifier will have far less effect on the overall character of the lighting than a strategy which relied mostly on the key light without adequate fill.
Conventional wisdom is that a HUGE key light modifier is needed to "wrap" the subject with soft light. But what is actually happening is that the huge modifier, used close, is simply causing the light to hit the object casting the shadow from many directions. It is performing two roles: defining shape and opening up the shadows. But because a huge modifier is doing both it is impossible to independently control the definition of shape and the illusion of hardness with the amount of shadow detail revealed.
A similar perceptual effect of "soft" looking lighting can also be achieved with far better independent control of those two variables by using two lights in a key / neutral fill configuration. The near shadowless fill needs little or no modification, and because the fill is there to lift the shadows it is possible to dial in lighting ranging from very "soft" looking to very "hard" lighting with a pair of lights with very small diffusers. Key light placement defines shape, the amount of fill controls the illusion of softness.
Chuck
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I will let her know 
I'll give both baffles a try next time out..should be interesting. 
she is tiny in person... just looks big in the shots.