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