#43 - May 29, 2009, 8:41 p.m.
There is a correlation between representation and balance, but it's not 1.0. Certain classes are more popular than others because players like the idea of that class or the play style. Certain classes are in low representation because they are countered by others who are higher. Certain classes maintain a high representation just because they counter other classes that are high.
It also matters how you measure representation. Are you comparing Arena representation to representation of the class at level 80 overall? Are you looking at all brackets or just 2s? Are you looking at all Arena teams, just the high ranking ones, or just the top 100? Or top 10? Those all give you different answers.
Some classes require more player skill than others. What you see in a situation like this is that among lower ratings, the class isn't effective because some of those players lack the requisite skill. Then you see at very high ratings, the class comes into play again because in the hands of an expert it's deadly. Does this mean the class is unbalanced because only experts can make it work or balanced because at the highest echelons where skill matters the most, it is in equal representation?
As the OP points out, being able to hard counter someone in very strict rock-paper-scissors style may be balanced but it's not fun. We don't actually go out of our way to make sure X is a class that beats Y. Certain classes will have advantages over the others just because of the way the class mechanics work out. We're okay with that to a point because it keeps things interesting, but we don't want you to feel you've lost when the doors open and you see who is on the other side.
