Not going into great detail on this topic, because I don't know much.  But if you're interested you can Google it.  The island of Borneo has three countries on it: Brunei, East Malaysia, and Indonesia.
There is also a West Malaysia where Kuala Lumpur is locate.  These two areas are like night and day. Kuala Lumpur is like Hollywood compared to third world East Malaysia.
And south is part of Indonesia.
East  Malaysia is the 2nd largest producer of Palm Oil and a major global trader in timber and rubber.
These are contributing to the deforestation of the island.  Countless villages have been displaced.

There are 32 different ethic groups with 80 local dialects. The Malaysia theme you read around town is  "One Malaysia".  Good luck with that.

The tribes I know or hear about the most are the Iban, Bidauyuh. Dayoks, and Ulu.  Mix those with the Chinese, Muslims, and the Timals (people from India).  There is actually a  tribe that still wanders around as nomads called the Penan. They are the poorest of all.
We see mostly Iban, Bidauyuh, Chinese, Muslims, and Timals.

The  poor missionaries get transferred all over the place. Learn one dialect and have a hard time in the next area with the language.  Basically once you learn Malay you can also speak Indonesian. 

We've only had two real lessons. We can say a basic prayer. And know a lot of other words.

These tribal people started moving into the cities around the end of WWII.  Many still live in the Kampongs or villages and haven't  move into cities yet. They are having a hard time adjusting to city life and are the poor and hard core poor. They move here because they want a better life for their kids.
Some don't get it yet and how it all works.  If they get a job and work for a couple weeks and they have some money they quit their jobs. They got some money so they are happy. If you give them a sewing machine to make a living they would sell it. It's like the traditions of their fathers talked about in the book of Mormon.  They have to learn a whole new way of living and surviving. This is a tough job. We got an interview for a girl, but she said she couldn't get to the interview because she had no way.  What do you do?????

Well that's my geography lesson for the day.