Don't actually draw the circle in the array, just the key points of it.
I guess I don't know exactly how he has his system set up, maybe he would need a second system for curves, but the point is to just use the array for key points in the circle (NSEW).
He is applying art to the array, so I would imagine he can work out a way to place the circles correctly.
For example, he could make it really easy and just set a few sizes (like 4) and then just line the correct art up to the points of the curve.