I don't really know what it is like here in the "desert", where bees have to live on rocks and dirt, to have too many bees or too much honey, but I do know there is more than one way to skin a cat (or a bee). My bees have never swarmed which is more the terrible conditions than good management, I fear.
Why don't you blokes go for a little extra brood room and then some nice honey super/s on top, depending on how often you are able to extract. Most I've seen round here limit it to one deep brood super and one deep honey super for convenience (directly related to those aforementioned terrible conditions, I suppose). Our hive stands need to be high here because of the ants and cane toads, so extra height becomes harder to manage.
Do you see much difference in numbers of bees or honey supply in your 3 combos, Eco? This might help others make decisions if you can record your findings about each hive. Are you saying in your 2nd combo you make extra brood space by taking capped brood above the excluder so you can put an empty frame below? (careful it is capped..I've read here that is ok but eggs or young larvae and you risk a second queen being brought out)
Paul, is every one of the 8 frames in the brood super completely full of brood? The bees can move honey around if they need more space there. Remember bees are hatching all the time and freeing up cells again. Have you thought of doing splits which will take some brood away and increase your amount of colonies too if you want to? I use an excluder so I am only assuming you are more at risk of a top laying queen too, which I've had a couple of times even with an excluder. If that doesn't happen, you'll just need to sort out the honey from the brood frames. The risk is disturbing or squishing the queen seeing as you manipulate the frames where she might be more often. I don't know if you've gone through a Melbourne Winter with them either, but beekeepers do try to put the brood together to keep them warmer, with full honey frames on the sides. If you have brood in the honey box you might be putting empty stickies next to them more often. I am trying not to extoll the virtues of an excluder, but I am personally more comfortable using them. If you are still worried about lack of brood room, the other option is to go vertical with another super.
The other question is, too much brood, do the resources go more to the brood than honey making? Maybe someone has an answer to this.