Hi,
We use 2 1/2 Litre auto drinkers on a post or wall and have never had a problem with them being damaged / moved - as long as you use ridiculous size fasteners to attach them.
We found that all the "Mischief" of playing with buckets and upending bowls was happening when refilling after they had run out.
With a constant supply of water it prevents crowding around as you fill and as they are sited about 6" off the ground then the pigs don't get their noses under them to root in the ground.
And as they are "Bowl" shaped they are easy to clean out with a few scoops of your hand.
We have sold a lot of these, probably well into the 100's for lots of uses, from pigs and sheep to dogs and chickens, even sold them to parks for dog drinking areas - they are virtually indestructible.
Thanks