Thanks for the answers everyone
Have gone with the majority opinion here and booked AUH-MEL in F
Entire itinerary on 1 AA award is: AUH-MEL in EY F, followed by SYD-NRT/HND-LHR-VIE in JL F. Super excited!
Edit: of course priced as 2 awards (AUH-MEL and SYD-VIE) but on 1 reservation