The only thing I worry about with zebra daniosis that they are a little TOO active for the galaxies...haha. I'm really just looking for a small fish who want really hide. Like I said. I have a ten gallon that looks like it's only got plants in there...haha
I recommend boraras brigittae aka mosquito rasbora. I have a school of 11 in a 14 gal along with celestial pearl danios aka galaxy rasbora, pygmy cories and scarlet badis and they are beautiful little schoolers. They enjoy some floating plants to rest in a bit, but for the most part do not hide and school actively. I think with your other fish you should choose a micro/nano fish. It will look better IMO...plus anything else is going to to scare your galaxies..they are very timid fish.