There is a big difference between the way Unidad reacts to you depending on whether you are in a 1-3 difficulty province or in a 4-5 difficulty. I have been clearing the provinces in difficulty order and when I finally got to monocoyo I was speeding along on my motor bike and passed a unidad soldier on the side of the road. In the lower difficulties i would barely get suspected but this time he somehow managed to catch up, ram me off the road and proceed to machine gun me from the turret. Lol i was like what the hell. Not complaining but was suprised to say the least.