Can someone smarter than me tell me how to hook a Helix G3N to a MinnKota Link?

If these are the only two things I'm networking do I need to run through a ethernet switch box? There seems to be a 5 port and a single port. And then there is a cable that hook into the back of the humminbird and convert to ethernet with out any boxes.

Obviously for these two things only, I'd prefer not to buy a $200 box. Can I get away with the cable only? It's call a AS EC QDE Ethernet Adapter