Rivals clustering up

I noticed that the rivals quit often seems to find each other now when there’s two fractions of machines in the game.

On the picture there is one one-to-one battle between a tank and a wolf, and a two-to-one wolf vs a harvester going on.

Are these fights ongoing while I play on an other part of the map or are they activated when I get close to the area? Anyone knows?

Only when you are close (~400m).