Three missing pieces of information: (1) What is the terrain? Are they growing on flat, slopes, or steep slopes? (2) What is underneath? In other words, will the cleanup be on bark mulch, stone, grass, or ??? (3) How compact are they positioned? What is the working room around them? Are they so close you cannot get between, or are they spread out? Are some of them growing next to a building?
These considerations would be important for me. Some of the other concerns have already been asked.