They can increase travel times, though they have to been travelling between two regions, IE they slow down movement on the road they are on. This was my key responsibility as a army infiltrator when I was in Arcaea. Many a time I ensured the enemies largest units did not arrive in time for battle. I never actually stabbed anyone in all my time as a infil.
Can even new infiltrators do this? Or do you still need well trained infiltrators?
