The truth is it seems pretty random. What's obvious is that the "withdrawals are processed in receiving order" is utter BS. Just now some people reports SEPA withdrawals clearing in 15/20 days, some others have been +5 weeks waiting.
International wires are processed in receiving order. No word about the processing order of SEPA withdrawals, but I suspect they start with the oldest and run through the queue while skipping those which are too large to fit within the daily quota. This means smaller SEPA withdrawals will have a small advantage.
If you have been waiting 5 weeks for a SEPA withdrawal, you should contact support and ask if anything is wrong. It probably is. Some wrong info perhaps, like joesmoe who misspelled his Japanese name, or it got in the international (SWIFT) queue by mistake.