I have 30 Arborvitaes on the side of my yard. I have never had any problems...
This long winter had deer eating a lot of ornamental plants - including some of my yews! They ate a good piece out of my 12 foot arborvitae a few years ago so now we wrap the bottom part of the plant with some old lattice to keep them away. It took several years but it almost looks like it should now. The key will be not letting them eat more of the hedge during the next winter. Evergreens just put on one flush of growth each year which is why it takes them a while to recover. See that your plants are adequately fertilized and water during prolonged dry spells so they can make lots of buds for next year.