I am working somewhere where they insist on using one mxd per region, in this mxd there is every layer required to make maps (about 10 per region). I find it tedious because you have to turn layers on and off and recreate the legend, and I find that since each region has the same layers if someone has another mxd open I can't edit layers.

What is the best practice? the idea was that there were too many mxd's being created, but I always thought it was better to have one mxd per map.