I would suggest the idea of a Packed Chart. The idea will be a char which the bubbles will only have a size value ( the will not have cordinates x-y) and Highcharts will calculate the best radius, and coordinates x-y for the best visualization.

As idea I will suggest see the following links: https://github.com/mbostock/d3/wiki/Pack-Layout and https://strongriley.github.io/d3/ex/bubble.html.