The hardest hub I ever had to take apart and re grease is a Stearmy Archer AW 3 speed.
All the bearings need to be greased and the planetary gears, even the pawl pins, the rest gets lubed by adding 3 drops 20W oil once a month.
The hardest part is getting the hub apart with out a vise, I had to use a very large pair of water pump pliers.