By - Jdick516
They're wandering so just wait until they separate
The reason I asked is because it has now happened both times I’ve gone to try and get the frost archer, I assumed that at least one of them would wander around at first, but the second time I wondered if that was just how it was and I just had to kill her with him there.
Tristen wanders around the roads of the farebane woods so if you see him just wait for him to leave the area.
Also as a tip to fighting the archer, you can let the bears out of their cages and kite them to the archer and they will annihilate her.
They are each on a different patrol path that happens to cross the other's at this particular moment. From my experience these timings and paths are quite consistent so you should just try a different time