Question about Wind River's ending (Spoilers)

So I re-watched this last night and I think it's a really solid movie. Sheridon is kind of created a meme of himself in many ways and this movie fits in that paint by the numbers mentality.

However, one thing kind of bugged me on rewatch. What in the ever living hell did the security team think they were going to do at the end?

First, they clearly try to out flank (1) an FBI agent (who may not have identified herself as such at that point but is clearly LEO) (2) Head of the tribal police for the reservation nearby (3) 4-5 Sheriff's officers (who may not have jurisdiction are still sheriffs) in an obvious attempt to corral them.

Then, they know their buddy is inside of his trailer packing a shotgun and they just lead the (now identified) FBI agent to the door? And then they automatically just start blasting all the LEO who saw the FBI agent get blown away?

Then what?

Like I get they were kind of in a shitty situation and all, but there has to be about 1000 better plans than this. It also appears they're former military and not complete idiots, so it's just a really bad plan.

And if you want to argue "they would have to clean up the murder scene" well...now they have to clean up a murder scene with like 7 ded LEO, 100 spent casings, across a much wider area, etc.