Twice now, I've attacked first and had to deal with a round of being surprised. The first time was
the gnolls by the cave
. I successfully carried out a sneak attack with a hide-in-shadows rogue. The second one was
attacking one of the strangely behaving sheep that couldn't speak to me with an Animal Speaking potion
when I could tell they were BS. They also got a surprise round on me. If anything, I surprised both of those groups.