Ah hahaha they are just two types of racing pods :) . There is no car/rider classification.

For my personal version I can use all Starcraft 2 units as racing pods, the dragon and the binocular pod are just a couple of free ones I found on Sketchfab and put in there to be able to publish it :)

Here are a couple of screenshots from personal version: http://emh.lart.no/publish/csb/million-mutas2.png http://emh.lart.no/publish/csb/csb3d.png