Thoroughfare hold-out

After the dropship 3 troops disembark in the far area, they're scripted to head for the lifeboat area (becoming the 'lifeboat group' as I've often called them), and they do so by skirting around a giant rock forming an outer corner of the rockslide. Meanwhile, when the dropship 4 troops disembark in the lifeboat corner, they're scripted to head the other way, towards the far area. All of this means there's quite a lot of toing and froing near the aforementioned corner rock. For the sake of having a convenient name, I call that general area the 'thoroughfare'. Quite a wide avenue of covie transit, starting near the rock itself.

The 'thoroughfare hold-out' plan, which I came up with in the course of making BCM666, is essentially to situate yourself near the start of the thoroughfare, to both attack and defend there. In view of the aforementioned covie movements, it can be quite interesting. Things also tend to be rather intense, and you may be coming under attack from multiple sides.

Two approaches

There are two overall approaches to tackling this, giving the general shape of the battle.

(1) If you get into position promptly (see first pic), without taking the time to free most restricted covies, you can potentially attack the dropship 3 troops as they're trying to head away from you. In this case though, you'll probably need to head over to the lifeboat area later, to deal with any remaining such troops, i.e. who got away from you. But of course, that can be fun too, and especially if you've got a well-stocked needler. This is how I played things in BCM666.

(2) An alternative way of tackling things is to do covie freeing before you get into position. On the minus side that delays your combat work, but on the plus side you shouldn't need to trek over to the lifeboat later, because the dropship 3 troops will have been freed from that territorial restriction.

Both ways have their appeal, so try them both and see what you prefer (with your particular set-up). Either way though, things tend to get pretty hectic, and you may well want to have chain-gun support.