The four tribes of Borka are the Dudas, Lakalis, Kan-Kans, and the Woodzis. They do not have a great government mainly because they cannot get along. However, they have decided to become one country by meeting in Synburg and discussing the governments. Here each leader of a tribe is going to choose a form of government for Borka.
The form of government I think will best suit the people of Borka is oligarchy. This is when you get three to four people running a country. Oligarchy is the best and most fairest because there are four groups. All they have to do is choose one responsible person from each group and they run that tribe. This way the people can go to their leader if they have a problem, and the leader can do what he can to try and fix it.
The four tribes each have something their good at and also they need or want.
They can work together to get what they need. The best thing they can do is trade, share their ideas, and cooperate with each other without fighting. For example, the Dudas are farmers which grow crops. On the other hand, the Woodzis hunt and gather food. They can get together to trade since they have different foods. That goes for all four tribes. The only way they can have a great government is by them trying to do so, which is to get along.
To end discrimination they have to do that themselves. That is the only way they will ever have a good government. They're given this chance to form a government so everyone can be on the same level. Not one tribe be the boss of another. I would set up a rule that if anyone is treated bad, the person will go to prison. This might make them cooperate and work together as one. When one's in trouble the other one helps him. Especially the Woodzis who are very scared of the others and teased by them. If they live on the mountains that's nothing strange. It's their way of life. They want to communicate with the others, only if the others give them a chance.
As you can see, the four tribes need a government in order for things to go smoothly. Oligarchy is the most proper government in this case since there are four tribes. They can share with each other what they have, instead of fighting, to form one country.