I read the article as meaning that the gang was part of the cattle grazing/farming industry. They burn the land, they bring in grazers, and by the time anyone notices the grazers have "been there for a while" so it's difficult to remove them, destroy everything, and let forest regrow.

That said, I doubt removing one gang will make much difference unless they change the system that allows ranchers to stay on illegally burned land.

Removing one gang usually results in another gang moving in on that territory. There's always a little guy looking for an opportunity.

Yes, (replying to all here) you are correct. I found the claim distasteful to say the least, and reacted after reading the article. In any case, I couldn't have done a better job of pointing out the fallacy of it than the mongabay.com page. I would've edited again right away had I thought anyone needs more convincing of the overall point.

The second paragraph of the BBC piece does say "The gang is accused of invading, logging and burning large areas of public land and selling these illegally for farming and grazing", and doesn't suggest which parts of that causes the most damage

Your link does note that at least some of the grazing land comes from squatters "selling" forest. This may be considered a form of that.

First you log, then you burn (to clean the land), then with the money you forge the documents for the land, and finally you move the cattle in. It's a process.