You're eventually going to find someone who says it will work. It typically doesn't. The problem is that clowns have their own personalities. I have a female perc that has a brain meltdown every so often and she kills her mate. It happened twice already. That's just how clowns are, and this behavior doesn't change when they're put in large groups -- it may even elevate this type of behavior because it's most likely increases stress levels of all of the fish. It also not a natural environment. In the ocean, we may see a dominant female, a male, and a few subordinates, but not a harem where all of the fish are from the same clutch or are the same size.
If you really want to give it a shot, go with a larger tank, primarily because you can house more anemones (more on this in a moment). I think a 34 gallon tank is too small; it's simply not enough space for the inhabitants but also the type of filtration you'll need to keep parameters in check given the high bio-load.
The reason that you want to have a lot of anemones is so the clowns can literally get lost in them. Aggression is minimized because they can't see each other. BTAs are a good option, but he tentacles of a BTA are typically not dense enough to make it hard for the clowns to see one another.
Better options are H. magnifica and S. gigantea as both species have lots of tentacles that are more densely packed than other nems. Assuming the clowns you'd like to keep are either percula or ocellaris, both of the nems are natural hosts, so the fish should dive in instantly and will remain bonded.
I have a 60 gallon tank (that's part of a 100 gallon system) that has seven gigantea and at one point had 16 Picassos. I recently gave them away to make room for new babies (I'm ramping up my breeding rack again) but during that time, they all managed to live together and all surprisingly grew to approximately the same size. The tank is "wall-to-wall carpet" and for the reasons explained above, it worked as well as it did.
