While I presume that shantaks lack the capacity to threaten villages due to their, for the time being, poor swimming capabilities, I am curious how the velocidohve would interact with them, since it doesn't have that problem.
Also, I'm going to make a wild guess that the megafauna responsible for some ruined older villagers would be the flumpus.
Oh, and I bet the communal janits will just love these guys. A chance at free food AND shelter from most beach-based predators?! What's not to love?