David
What you have experienced is very, very common with new players. I am SO GLAD you didn't post that over at BGG, or Kevin Duke would have taken you to task in a big way (he's mellowing with age, and our help though, and he's actually not a nasty guy, just short on patience sometimes :blush: )
It takes about 5-10 games of CC:A before you "get" it, before you figure out how the design is working. A great many things are very unusual at first, but after a great many plays, you begin to see how things like flanks are portrayed in the game. One weakness in games with "flanking" rules that are more explicit, is that they seem to degenerate into turning engagements, not unlike jet fighter combat, with each side trying to turn hard enough to get onto the other's tail, so to speak.
From what I've read, this sort of thing didn't happen until well into the battle, and for each successful flank attack, I can find you a flank attack that failed after the defender rapidly reformed to meet the new threat. The Romans and Alexander's phalanxes were both very good at this. At Gaugamela the Macedonian phalanx pulled a totally unexpected 180 degree turn, and marched back to secure their baggage train from plunder.
This game achieves flanking in an implicit way. You drive off the Light Infantry covering his flanks, and then hit the end of his line. With luck (ie your troops actually do their jobs as advertised) you will set up a cascading series of bad retreats for the enemy, steadily rolling up his line like a cheap carpet. It doesn't work every time, but when it does, it is nothing short of spectacular, often resulting in an outright win a couple of turns later.
And all this with only one little rule - support. This design is not to be taken literally.