PVE. It doesn't need large pens. I shouldn't have to make an ugly, enormous barn to keep things ordered. I should only need a simple barn for livestock, and then be able to have defensive tames hitched so that they don't run off all over creation.
The solution? Yes I have them set to follow a passive tame so they can run off, run back. The problem? They like to run into the ocean and drown.
The other solution? Crabs. They won't drown and they'll wollop pretty much anything, including some alphas. They're just so huge, they cluster in a shitty pile.
The benefit? It would reduce building bloat and the need to render building tiles, keep tames where you want them to be (as long as they're saddled, they should be able to be hitched)
Today I witnessed a bear get bumped by an alpha horse, the horse kicked it and everything piled on it. The horse ran into the sea, and so did the bear and two crabs. What happened then? A shark attacked it and it swam further out. The bear and crabs made quick work of it, and I was able to retrieve everyone and put them back into their appropriate hidey holes but what about when we're offline, or out and about adventuring?