A tank with many dwarf gouramis can work as long as the tank is large enough (at least 20-25 gal, preferably more), has plenty of cover and you keep only one male with several females. In your case I wouldn't recommend getting more gouramis, especially since I don't know what sex yours are.
If the ones you have continue to fight (assuming it's a couple, male and female) you can either provide a lot of hiding places and plenty of plants, or if one of them gets too stressed or is in danger of injury, remove one and just keep the other, maybe with some other small friendly fish. If they are two males, remove one of them now, since there's not much chance of them ever getting along. Two females can be surprisingly aggressive towards each other too if they don't happen to like each other, but this depends a lot on their personalities.
Probably not the advice you want to hear though, sorry. A group of gouramis would be a lovely sight, unfortunately the gouramis themselves usually do not agree.
There are a few gouramis you can keep in a group. I believe the croaking gourami isn't very territorial, but they can be delicate and hard to find.