I have several cherry barbs, currently at a 1:1 ratio, but my plan is to add a few more females. Mine live in my 55 gallon. As Ny82 said, they are active so they need more than your 60 liter could provide. However, if you had a larger tank, they are rather peaceful and don't bully anyone very much at all, so they should do wonderfully with your honey gourami (based on temperament, not sure about water conditions). The larger the school, the better of course; however, the more females you have, the less your males will bother them. When I first picked up my group, I accidentally got five males and one female. My plan was to introduce the boys first and then the girls, but one slipped in. My point is that the poor girl was so stressed I had to immediately buy more females. Right now, with a 1:1, there is very little stress, but when they are trying to breed, they get a little bit more rambunctious. Maybe you could add two more females to your proposed group, which should level out any stress due to breeding.