Markers added directly to map: depending on the scale they can hide each other.

Markers added to map through spreader: if several markers overlap they are displayed next to each other.

Also: check out the labels!

Markers added to map through collator: out of several overlapping markers, the one with the highest z-index is displayed

Both spreader and collator used here: orange markers are collated while teal markers are spread.

OSM map with markers added directly to the map

OSM map with collated markers

Sample markers on Google map

Sample markers on OSM map

Circle on Google map

Circle on OSM map

China on Google map

China on OSM map