I'm not sure if I understand you correctly, so let me know if this does not answer your question.
Case 1: One marker will be drawn first and will hide the other marker if they have the same size. It is not specified which marker will be drawn visible! If you want a specific marker to be on top of the other you should either hide the other (enabled = false) or use the renderingOrder property.
Case 2: Sensitivity currently is a precision of 6 after the coma. If you know the nearest poi, you can disable the POI further away or set the renderingOrder property.
If this does not answer your questions just let me know and please provide screenshots.
about 5 years ago
Case 1: (The same location behavir)
I create markers with the same AR.Geolocations such as below, the result disappear nothing, according to my server I get some the same location and last coming one should be shown with title. Why this happen?
I create markers with the nearest eachother. Only marker2 is shown on the cam. a) What is the sensivity (rounding issue) I read this forum (URL) but I must show the nearest poi, b) how I do that Can you suggestt me a method?