Read the rulebook, plan for all contingencies, and…read the rulebook again.
The counter shapes correlate with no game mechanic. They correlate with the spaces in the insert. The driving idea here is that the artwork is all scaled to the miniatures, which are either 1/285 or 1/300 scale, a very traditional size for games like this. But the sizes do not have an AU or VP equivalent.
I'm glad it correlates to something. But it would have been a nice mnemonic if they correlated to AU cost.