Jim, it is the walking base, including the correct passing note that is difficult to emulate with an arranger. Nothing wrong with your changes on this one, just a missing bass change that you'd have to play manually.
Good work. This issue is why I stopped using arrangers for live play.
Lets visit as soon as it's safe.
Russ
Walking bass on an arranger can be a problem. It really needs to be played manually with most arrangers. I remember playing Masquerade on an arranger and the walking bass line was an issue. I wish there was a way to make the left hand chord bassline simply move to the closest chordal bass note rather than the root of the chord. That would implement walking bass pretty well I think against the auto accompaniment. Being a computer programmer myself that would seem like a relatively easy function to add.