i would say that in a less game-y setting the mimics would just tend to go for objects because mimicking living moving things makes it blitheringly obvious that they're mimics, i mean just look at how much we actual humans struggle to animate realistic humans without people finding them horrifying.

But like, it would be totally fair game to be fooled by a human-shape mimic if it's in a dark room or something, though probably you'd still notice it's a bit weird when you get close (but that may be too late)