Well, any ethernet card will require drivers. Apple got around a bit of the problem by allowing the developers to place fairly high level code in the ROM of NuBus (and, I assume, PDS) cards. The developers of ethernet cards tended to get around the rest of the problem by making their cards compatible with Apple cards so that they could use the Apple drivers (that were bundled with System 7 and later).

So I'm guessing that yes, one port will work. If the two ports behave as though they are on a hub, then both will work but it will only provide you with one ethernet interface. (And, if my guess is true, that would be the case both with and without Farallon's drivers.)