If the scale of the smaller object is close to the scale of the larger one, there is indeed some depth fighting between both outlines, however, as you decrease the scale of the smaller object you might notice that the larger one's outline should effectively overlap the smaller one's outline.
In order to best help you, I'm going to need some further information regarding the specific effect you're looking for, if possible being exemplified as a video or a screenshot, so that we can point you the right way, thanks!
Unfortunately, this type of behavior is expected and not an easy one to manipulate. I would suggest looking into the Render Queue parameter of the Output node and the Depth options, in order to try and approximate the results to the shared image. Despite seeming like a simple depth issue, it might have further implications regarding this technique.
As requested in my previous post, providing further information regarding the specific effect you're looking for, with additional details such as the application and expected final result, would hopefully allow us to point you the right way.