Bud, I don't think the keyboard manufacturers really copy the styles
of eachother, but maybe the sources are very similiar?
If you pay the intro's etc. good attention, you will often hear that it
will point you to one song or another who was/is popular in the time
close up to the date those keyboards was released, or songs popular
within the category of choosen musicstyle.
This you can hear in the additional software too, even if they like to
call it "allround", and of course even more in the songrelated styles
available.
Yes, the styles will always sound best on the keyboard brand they are
buildt to be played on, regardless to manufacturer and model.
I think Alec's reply for Larry is a very good description about those
matters.
GJ