Ditto what Dog Folks said. The nylon tie-outs we use can be shortened if necessary (similar to how you adjust the length on nylon adjustable collars). And if we're in a really large site I use their leashes to add extra length.
The main problem with tie-outs is preventing the dog from getting tangled around stuff, and in the case of two dogs, preventing them from tangling with each other.
Many people use exercise pens (often referred to as ex-pens or x-pens). Here are some examples from Amazon:
Ex pens