Technically it will work with a single initiator port in every head; but it is highly recommended to have two ports in every head for MP-HA (MultiPath-HighAvailability) cabling. If this is a new system, it should be already configured and delivered with MP-HA from factory.
Yep, fair enough - there has been a change to quoting tool which I previously missed: MP-HA box now cannot be un-ticked when building 3000 series system; interestingly enough the MP-HA option isn't forced on 2000 boxes (although comment remains the same that MP-HA is required for A/A systems).