I've seen a lot of maiden names as middle names in my family too - including one where I have not yet found the original woman who passed on her name.
Sometimes, however, the middle name is a location, which, if the name could also be a surname, can lead you well off-track. I had a few of these (e.g. Richmond, and Clifton), but I was sceptical about Augathella from the outset!
The location most often used was the birthplace of the child, but could also have been the birthplace of either parent (particularly if they had emigrated). Around 1915-1920 Anzac and Gallipolli became surprisingly popular middle names for boys in Australia, possibly due to the media reports of the WW1 fighting there, or maybe the death of the childs father there. I've seen other battlefield names used as middle names too.
If the name is a location, its sure to be another clue to follow.
Sandra