Miller took 3/27 on the final day, helping to cut through the middle order as Australia won by 274 runs.
From the middle order, he scored a single run.
Brown managed only 24 and 32 in the middle order as Australia won by 409 runs.
He came back into the side in the middle order but continued to struggle for runs.
The rest of the top and middle order fell without a large change on the scoreboard.
As you say, the middle order hasn't looked too clever so far.
He plays as an opener but can also appear in the middle order.
Head remained a regular selection for the 2012-13 season, usually batting in the middle order.
Batting in the middle order, he scored 13 and 33 not out.
They need to look at the age bracket of their middle order.