It's not the same if there's a bulkhead in front of D-F and none in front of A-C.
And back OT - my argument is you're paying to add 3Kg to an allowance that on many routes/airports they won't weigh.
There is a bulkhead in front of both sides on VH-VFD.
Again they have always weighted my carry on, so I'm paying for certainty.