I have seen one very neat antique tool to tighten fence. It was in use by an old gent on a fence tht was basically on the ground. It was nice and tight and standing tall in very short order.
The tool was a plier like contraption that had 2 prongs on one jaw and 3 on the other. Place on wire, squeeze and it left 2 crimps just like you see on hog-wire.
I looked in catalogues and junk stores with no luck so I built my own. 10" vicegrip with 2" angle irons that nest welded to the jaws. Walk down the fence, put 2-3 crimps between each post and wire is tight with no weakening sharp bends, no screwing around with tighteners, no need to loosen staples. Wish I had seen one 40 years ago.
If you want to try it, clamp a couple of pieces of wire before welding the angle irons. I didn't and it makes it a bit awkward hitting the same crimp each time.
Harry K