When it comes to defoliating I think it's a good idea to be tactical. You want to keep as many leaves as you can but you want to expose as much internodal growth as you can. If you see a fan leaf blocking a top you will get more out of exposing the top and increasing air and light penetration.
If the growth is too low on the plant it will never produce top quality so you get more out of removing it and telling the plant to focus on growth with better potential. You always want to maximize on the energy your plant is using. When your plant is recovering it's not using all of it's energy for growth so it's always a cost benefit analysis. Don't defoliate a burned leaf thinking you will stop the burn. The absence of the leaf draws more nutrient water higher up the plant where more leaves will burn.
All in all I think you get more out of defoliation than you lose as long as you approach with caution.