The gold in a level 5 barbarian city is a very very tasty score but the question is what size army do you need to take out their forces with minimal casualties?

Barbarian cities always have their gates open so you have to fight both the army and the defenses

750 warrior
1000 pikeman
350 swordman
250 archer
200 calvary

3750 traps
1875 abatis
1250 archer tower
750 rolling log


the gain:
3,000,000 food
180,000 wood
180,000 stone
180,000 iron
950,000 gold

So what do you guys suggest to send in order to win and make it worthwhile?

This is the only scenario I could find on the forums about fighting a level 5 barbarian city: http://bbs.civony.com/showthread.php?t=1752

I'd rather not lose as many troops and I want to send enough workers/transporters to wipe the town clean.