Alleged experts will tell you that as much as 50% of the top growth should be thinned out of trees at planting time to compensate for root loss. First of all, if the tree is container grown, there is no root loss - all of the roots are in the container. Thinning also isn’t needed on balled and burlapped trees or bare rooted trees either. Leaving as much of the top growth as possible gives the most foliage to collect the sun’s energy manufacture food through photosynthesis and grow roots so the tree can establish quickly. I admit - there are two exceptions - both live oaks and yaupon hollies dug and transplanted from the wild do benefit from thinning. On all other trees - save the time and money leave the branches and limbs alone.