Not to belabor the issue (sorry), but if it is networked, it is connected to a machine. Any machine. Because all of them are connected to it via their own Ethernet through either the switch or shared form the server.
Certainly, if it works for you, that is great and, again, I should stay out. I guess I am just throwing this in because 1) to help others, and 2) because I can't help myself -- probably more the latter.
But, the fax machine should be able to "see" the server. It is always better if it is networked and any machine can access it so a workstation doesn't have to spool and control the print or fax. If that station goes down or is turnedoff, then no one can access the fax.
I think it is all a matter of logistics, but I would cringe if my networkable printer or fax HAD to be connected directly to a workstation.
