My explanation:
in the A330 you have to land in CONF 3 when you have an engine failure. So you have to make a landing distance procedure, only because of that. With flaps 3 you will use more runway. As you know, in the table you have to use flaps full VREF and add any deltaVREF. In this case, deltaVREF when there is an engine flame out is 5 kt, due to the fact that you are actually landing with flaps 3 instead of full. Not for any other reason. Also, you will have a few spoilers less, because the 330 has no PTU. This affects the landing distance factor.
Now, in the 320 you can land with flaps full, so there is no need for any abnormal configuration landing and you have all spoilers so there is no need for landing distance procedure, except if ther is icing conditions and you have isolated the failed engine bleed (XBLEED SHUT) due to an engine damage (every time you push the fire shut off valves out you are "declaring" declaring the engine as damaged and will have the XBLEED SHUT blue line in the ECAM). In that case you cannot use Wing anti ice, because you must not use it in only one wing. Then, because of the icing conditions, you have to calculate increased landing distance and a delta vref to account for the ice accretion.