3 engine ferry certification is usually for one engine inoperative, not missing.
The BAe 146 ‘engine missing’ event was approved after design and simulation reviews of the effects of asymmetric weight and roll control; they were insignificant compared with the basic fuel imbalance and control requirements. However, because the configuration had not been flown previously, the certification approval to ferry required that a manufacturers test pilot was captain, which in turn required local authority validation to fly the foreign registered aircraft.
The 146 event involved many more aspects of airworthiness - collateral damage and temporary repair, overland only and one refuelling stop.
The #3 had failed, but the #4 pylon was damaged such that an engine should not be fitted for ferry; gear down unpressurised.
The A380 should be easier to approve, after all it arrived in that condition.
Assuming that there is little collateral damage, then a ferry in the current configuration should be feasible. However if the engine has to be removed, then there could be a choice between approval to fly without it, or shipping in a new engine and repair team.