You make me smile bill . Isn't an entertainment organ ......just an Expensive organ with errr .........an arranger inside ? Ha ha ! You could do stand up comedy honestly !
And I did not know that a midi keyboard and an additional computer and external software was "one instrument " or could meet the fluidty and ease of use as an arranger but i guess anything fits the description of one musical instrument in your world if you really really want it to ...... As always it's been fun .
The arranger comes from the entertainment organ not the other way round. (Talk about twisting the facts)
You asked for 1 option and I gave you 2, 1 which is an all in one (Like an arranger) and a second which weighs no more than an arranger and has minimal additional setup if you are gigging.
Just because you like an arranger, doesn�t mean everybody else in the world should too. (Everyone has a right to their own opinion)