You say this like 50 times a month on this forum, but a little research will show that most horticultural institutes believe this to be false. You prune back to have a shorter trunk, thats it. The only way the above will help, is if you are pruning to fit the tree into a mist bench or something. I am not saying your trees will die from top and bottom reductions,
just that doing so to help the tree is proven to be ineffective.
http://rangerservicesinc.com/Articles/ISA Top 10 Tree Myths.pdf
http://hort.ifas.ufl.edu/woody/pruning-needs.shtml
This is the result of like 5 minutes googling. I don't even have time to look back at pdfs, lecture notes and books that stack up time and again to say that pruning after root loss
is not beneficial for tree establishment/recovery.