Stacked column bar chart limitation?

What am I missing here: I have created a stacked column chart, with three bars. Each has two percentage values for comparison: the goal and what was actually achieved. When I generate the chart, AI stacks the charts instead of overlapping them; instead of showing the 25% section against the 30% section, it puts the second value on top of the first, so that column actually reads as a total 55%, which is not what I want. The only solution I could think of was to create the chart as a simple bar chart, ungroup everything, then manually move one section over the other: Please tell me I missed a step and there's a better way to do this! Below is what I ended up with.