Buy Light Pistols (for Sport) Spypistol(for sport and Labor) and Crosbow (for Beach). The Nailgun (the big one, not the Stapler) also works for Labor. Check what you can use and buy it.
Stay in the dark and shoot them from there, they don't have sniper spotter at this level and have nothing they could do.
What I do here is pretty scary, since I have no guns for this mission, but only one of them has one, so it isn't that scary.
Oh, and send the expendables to the forefront. If things go highwire, retreat.
There isn't much else. Don't get shot is the real deal on these missions without armor.
Against ninjas I will use the Scout Drone since it can see them from 5 tiles more and send bigger group. The VAN can't really take on a Black Lotus Outpost and above.
So, walk forward, look for the assassin, retreat. Dogs are also useful for the Track, especially on the HQ. I don't think that Assasins show up on covert missions. At least I haven't seen one. Warriors do, and they look exactly like Assassins, but don't have camo.
