You don't require a hub unless your network wires out number the ports on the MFD. Unless you are needing a hub to run 24v; I would save a few bucks and use an off the shelf hub with the TZT3. Power sync feature offered by HUB101 isn't used or needed with TZT3. While the hub101 is a good product, unless you need something special from it (like running 24v or power sync) I would save the cash for a diffrent upgrade. If you have NMEA 2000 items; yes you will want to build a 2000 bus and connect all the NMEA 2000 items to the bus. If you only have the MFDs and no other 2000 items then you don't have to have a bus. If you build a bus, all MFDs should be connected to it.