Rangers suffered similar setbacks when they were competing in Europe. A common theme in Scotland is that clubs inexplicably regard themselves as superior to other European teams, the complacency you mention, yet when it comes to the pitch, these other teams regularly prove technically superior and progress to the next round. Aberdeen, Hearts, Motherwell, St Johnstone, and Hibs have all crashed out to teams you might describe as 'shit'. Perhaps seeing them first as equals if not superior would be a step in the right direction.