I used to work at Keysight's spectrum analyzer R&D group. They do this to simplify their manufacturing logistics and to try to get volume production efficiencie

I used to work at Keysight's spectrum analyzer R&D group. They do this to simplify their manufacturing logistics and to try to get volume production efficiencies. The monthly volume of any one particular SKU is so low that if they didn't combine all the models together, they would essentially be custom making everything.