Hey,

I see what you mean. I don’t think that qualifies as bug though 🙂 More like a design choice. 🙂
Please let me explain why it’s made to make use of center rather than X.

Here is a screenshot of how it works now. Visually, the connection lines and the position they are touching the nodes, indicate which node is first and which one is second.
[attachment file=”PosXCenter.png”]

If we change the sorting to be done by the nodeRect.x rather than center.x, then the connections (in some cases) no longer reflect the order of the nodes and can lead to visually being criss-crossed, which I think can be quite confusing.
I really believe that in the following image, the top action node should be first in order 🙂
[attachment file=”PosXMin.png”]

Is such a layout that you have and mean by “step ladder”?