Hi Spalding
Compare the specification of a Workstation and an Arranger, and you will find that the Workstation has more real time controls for on the fly use when playing live, whereas the Arranger is pretty much a pre-set instrument.

Home users want something easy to play, (Instant gratification) and real –time controls and in-depth editing have little relevance for most of them.
Pro users want as many real time controls and on the fly editing as possible, so that they can let their imagination run wild, and really spice up a live performance.

As you can see from the above, Arrangers and Workstations are completely different animals, and while there will always be some similarities, one cannot replace the other. (There is no one size fits all)

Regards

Bill