As mentioned, there are too many design paradigms with overlapped audio/lanes/track versions so you end up getting unexpected behaviour with specific use cases. Perhaps try filing a bug as it seems you can not accurately choose which audio is overlapped unless you change the events via lane order.
As a work-around perhaps try slipping the audio (shift + click on the audio in an event to slip left/right) to fix timing or using the newer “'beat detective” style multi-track editing and quantize features (- YouTube). Personally I always have delete overlaps on as this keeps the session clean. It’s very easy to drag a split point now as moving it will lengthen one event while shrinking the adjacent one requiring no cleanup of event lengths around an edit point.