They don't need to actually change their behavior in large numbers. We wouldn't need to have like, a village of male viera somewhere. Have a small handful of scattered npcs and leave it open to the player to decide if they play a male viera what their character's deal is.

Or the situation where they live gets so desperate some of them agree to work with the WOL to save their forest etc, and they haven't so much abandoned their ways as they're pushed into a bad spot and forced to accept help.