So, I’m not very good at this game, so I don’t have much combat experience outside of the archipelago.
But today, I finally made my way into the farmlands again. On my way to the bunker, I wanted to check out a downed jet, so I tried to take out the three runners guarding it with a trap. But as soon as the radio that I placed in the middle of the field started playing, five hunters came out of the woods and two tanks came charging from the horizon.
So unless I’m doing something wrong, radios and such seem to be useless, because they bring in much more enemies than I wanted to take out.
It could also be that there was a Seeker (the flying ones) around, and if it heard the noise and went into its alert mode, that really attracts attention of other nearby machines, such as Hunters and Tanks. Seeing how quickly a Tank reacts to a damaged Seeker is a little bit alarming.
I used to feel like I got swarmed by lots of enemies earlier on in my playing of the game, and it caused me to take a more methodical approach. I make heavy use of binoculars (and an IR Vision attachment is nice if you can manage it!), but also sound cues. In general, the sound is very good in this game, especially when it comes to directional sound. If you look around, you can usually HEAR a group of Hunters moving around, even if you can’t see them yet. That is how I check an area before I plan out any kind of trap or other combat engagement.
Radio, especially Boombox, works over a large area and is bound to draw in any machine in hearing distance. For a lure that doesn’t have that large of a range, use Flares instead. Flares work on visual basis and not sound basis, so, only close-by machines that can see the flare are drawn to it, and not other machines behind hill/corner of a building. Also, flares weigh a lot less and can be thrown quite far.