That certainly sounds right in theory but in practice this will not work depending on the number of devices. I have had success with a max of 7, others have reported success with 10. Once you exceed the max your hub will allow, you will receive an error message telling you that you have exceeded maximum USB resources.
I'm saying there is three USB 3 ports on the docking station, attach a 10 port hub to each of those and you'll have room for 30 devices, then there are the USB 2 ports (also three I believe) they could take 7 port hubs to those. The final number isn't really relevant, you'll have more than enough USB ports available for your usage scenario. Windows supports 127 ports, but I don't know of any computer that does.