If they do send the A320 to Europe before LHR it will be an early start. the current block times are 2:40 and 2:45 respectively. There is currently a 50 minute turnaround at FAO, for example, but that could be a little shorter.
SNN 0600 FAO 0840
FAO 0920 SNN 1205
Its not impossible, but its very tight. Its entirely possible that EI may be able to shuffle slots around and get a later departure from SNN. Nothing from ORK, DUB or BHD really fits the bill, good job IAG have a lot of slots, if needs be. The alternative is that EI think enough people will want to fly from SNN to FAO at 0540, or they plan somewhere like AMS or CDG with shorter flight times.