That does look like squirrel damage. We don't have a great explanation for why they do this, but it seems to be mostly females that do it when they are pregnant or nursing in the early growing season. Some nutrient they are after? They likely are doing it on a border of the orchard and yes the same trees or at least the trees in a common area tend to get hit repeatedly. A trunk guard may help, but they will also climb into the crotch and strip bark up high. You could try one of the rodent/animal deterrents. If you can manipulate the habitat around the orchard border where they are active that could be the best thing. They feel safe coming over into the orchard, there may be some cover that gives them protection. They need to be more afraid to intrude.

In general if a tree loses more than about 1/3 of the bark and cambium of the total circumference, if will suffer tremendously from the wound. More than 50% it will probably die a slow death. That tree in the first picture is never going to be a good tree. The second will likely recover and be OK.