I think what enki said is true. Its hard to see in a biorb and even harder fr the fish in there. Plus, to decently decorate a tank/plant it, you need a big area on the bottom, not just the little plate size at the bottom.
but
minimum tank footprint for neons and zebra danios is 24" due to being fast swimming fish - danios also need to be kept in groups 4+ else will get stressed
golden barbs need to be in groups 4-5+ and need a tank footprint again of at least 18-24" minimum
only letting you know as information - upto you what you do with it good luck and does look nice for a biorb
its very nice
but the barbs shouldnt be in there i have a group the same and they like to swim fast sometimes, they cant do it in a biorb why not take it to the store and swap it for something else,smaller and not so fast.
ive had and have biorbs and yes they are very tricky to get to look nice, but i think youve done a grand job what looks really nice in biorbs in real plants, java fern does nice in them,maybe tied onto a small peiece of bogwood?