Although the same arm-rest setting is supposed to work on any Airbus, I find that there are small differences between individual airframes (unsurprisingly).
Even so, I always set 'C5' and the pedals at '8' and then see how it feels. 9 times out of 10 it's fine; occasionally I have to tweak it. Seat fully up and forward until the inboard arm-rest is visually just against the cut-out in the centre console.
Saves time and works for me! (6ft 3in with long legs/arms and short body, in fact a passing resemblance to a gibbon)