This short tutorial shows a couple of ways to solve the situations where multiple series can have label bullets shown, and thus may overlap with each other.
Repositioning with an adapter
We can use an adapter, to dynamically check for overlap with other bullets, and change bullet's centerY setting, so it is either moved down or up.
See the Pen Solving bullet overlapping by amCharts team (@amcharts) on CodePen.
Differentiating alignment
Another option, is to use different alignment of bullets for series.
See the Pen Solving bullet overlapping by amCharts team (@amcharts) on CodePen.