Some do, some don't.... I've had mixed experiences with peppermints and some LPS. Often, the shrimp are stealing food that the acan captured. I've had others that never looked at an acan.... but did like astrea that had fallen on their sides. Shrimp are opportunistic feeders. Keep them well fed and you usually don't have issues...... usually.
+1 on the some do, some dont thought, on the acans, and getting along, if a skunk or two have time to settle in, and become territorial they may, or may not kill an interloper, of different or same species, sex and maturity could als be factors.