I am not suggesting we should go back to the wholesale destruction of habitat and hedgerows that occurred in the past but I think that the pendulum has now swung too far the other way.
Agriculture, like every other industry has to be run in a responsible manner, and overstocking sheep in upland areas is not responsible, but if you do not graze the land gets over run by bracken! I confess I am puzzled that it has been considered to lead to deforestation, most of this land has never had much in the way of trees on it anyway. Look at any landscape paintings of the past, trees in the valleys, but not on the uplands. Not until the Forestry Commission came and planted pines everywhere because it was all that would grow on the damp acid soil of most uplands.
I think farm stewardship plans, where conservation goes hand in hand with farmers is by far the best way to protect habitats, but when protection of habitat is clearly damaging to existing human occupation and land use then those in possession should be preferred.