Kamilaroi,I think you are getting a few descriptions mixed up somewhere unless my 1992 edition of Coggers book is differentt to yours, Western Brown,Pseudonaja nuchalis 1.5m total length, Fierce snake, Oxyuranus microlepidotus 2.5 m total length. A 3m one would be a monster although I have seen a 2m eastern brown.
Coggers book doesn't mention temperament but another book I have by Raymond Hoser decribes the western brown as aggressive but not as aggresive as the eastern when disturbed.It also describes the inland tiapan(fierce snake ) as not at all agressive and more placid than most other deadly snakes.
This just goes to show all the conflicting information there is about snakes.
cheers gaff