I think maybe what helm and adarias were trying to get at is that while muscles can only become larger or smaller, you CAN focus on specific muscles (which change the shape of your body) and more importantly you can also increase muscle strength WITHOUT increasing muscle size.
Muscles groups do not work independently of each other. A stronger back will give you an edge when you work chest. Building stabilizing muscles will make exercises with primary muscle groups easier. It's near impossible to build a good chest without working your legs (since working your largest muscle group, quadriceps, is the fastest way to stimulate your body's testosterone production). Your last statement runs contrary to every kinesiology study I've read. I would like to know how you reached that conclusion... If you're thinking about body weight exercises or high rep-low weight, that's a ratio issue, and those do increase muscle mass (just not very quickly or effeciently).
Bodybuilders/models tend to focus on the muscle groups that LOOK the best, and they work very hard at increasing their size, NOT their strength. How many of these bodybuilders could actually compete with the relatively flabby-looking atheletes who dominate the olympics and "world's strongest man" competitions?
They don't compete because they are different sports. Gymnastics involves building muscles, too, but those athletes don't compete in these sports either. The difference between the two are akin to the difference between Kada karate (form) demonstration and karate match. The athlete needs a solid foundation in karate for both endeavors, and there is a little crossover between the two, but the goals are very different. Likewise, bodybuilding pits the athletes against a hypothetical visual ideal, while weightlifting pits them against each other using weight as a judge.
Let me break this down.
Bodybuilders - the goal is a shredded, muscular look (super low body fat). Because the competitions are more like dog shows and less like an athletic tournament, they dehydrate themselves for their routine (to further muscular definition). In the off-season, these men are typically 30-50 pounds heavier, and put up a great deal of weight to increase their muscle mass. I will repeat this because it refutes your point: a bodybuilder must be strong to increase his size.
Here is an example:
Nasser El Sonbaty is a pro bodybuilder, and in this picture he is holding 380 pounds. The muscle is not all show, trust me, that's a good deal of weight.
http://www.bbcenter.sk/images/gallery/arnolds_classic/nasser_sonbaty/sonbaty12.jpgWeightlifters/World Strongest Man - the end goal is raw strength, the ability to move heavy weights or hold the second digit of a TUT. They are not awarded points for their physique. For these rigourous physical trials, they MUST keep hydrated and often will rely on higher fat percentages to give themselves an edge when dealing with heavier weights. (For example if there are two men of equal strength but one weighs 50 pounds more, the heavier one will have an easier time pushing over a 450 pound column).
Mariusz Pudzianowski has won the World's Strongest Man competition three times.
http://img302.imageshack.us/img302/2623/gallery131296260ed.jpg (on the left)
http://www.pudzian.pl/foto/235.jpg (on the right)
He weighs a bit more than Nasser, but is much stronger (record bench is at 606 lb) though less cut. However, they are both strong men, no matter how much you claim that muscle can be for show.
This is the biggest thread hijack I've ever contributed to. To increase my post's relevance: I think the RGB experiment is a great idea for the aesthetic. Without the black, it reminds me of a relief sculpture, with shapes protruding from the visual plane.
Helm: I agreed with the descisions you made regarding the look of your character. The anatomy is another issue altogether, something I did not address.