I think the simplest answer as to why the different strongpoints originally is probably because M.Benninghof designed NoE and used Airbornse s/points and M.Perryman designed the other 4 sets of 10 and used Cassino s/points.
How that all got muddled up with creation of IoG and also then got to include Edelweiss s/points ? I'll leave that to others to ponder :-)