I'm not sure you read my post through.
That whole thing is the pump assembly, the pump itself is only the lower portion, while the upper portion contains the sending unit (the arm) and the 3 ports.
You do not need a vent on the tank AND on the pump assembly. The third port is EVAP. If you re-read my post, it explains your options. You can hookup the EVAP like o.e., or just run a vent or vented cap.
Vehicles that use an external pump (so, not having the whole sending unit assembly) will sometimes have a vent on the tank which will either vent to air through a breather or a charcoal cannistor, or just use a vented cap.
You do not need both, tho they both pretty much serve the same purpose.