Bachelor's degrees in the USA are 4 years long so when they say you can substitute 3 years work experience for 1 year of uni it works out to 12 years. Some visa agencies say different and i know a person who showed an economics degree when asked for their degree at the consulate applying for an E3 to work at a regional. Most people I know who went to the USA on an E3 just showed their pilot licence and medical at the consulate and that was good enough.