Ideal way to do it , if you know for sure your graft is going to take and you know for certain that is the tree you want there... When I do go direct to the field I do everything the same as if it were a larger tree (large cage and stakes and window screen - ground cleared around tree with a small water catch berm) Personally from my perspective that move (direct planting) is to save time and effort so I wouldnt waste time by just doing smaller scale protection then later have to come back and put a larger cage around the tree. Do it all in one shot as if it where a larger potted or bare root tree. Only draw back is I can baby them (water and sprays) in a nursery till they are larger and get through that 2-3 year crossed finger period.