Had to sit and think for a minute and go back a lot of years but the number of Arrangers I've seen played in pro situations I could count on my fingers, no toes needed. Not counting a few I've seen who just use their Arranger to play backing tracks. Just counting those that are really played.
Here in SC there is music all over but only one guy uses an Arranger
( BK5 now a Yamaha ) and he uses it just for the drum patterns in a duo with his wife. He plays LH Bas and RH chords. She does all the fills on a Keytar.
Three other acts use drum machines, no arrangers. Everything else I've seen is all live. The other thing I've noticed is the Backing track thing which I saw all over in NJ is almost nonexistent here. Only seen one guy doing it.
I don't see much of a future for Arrangers in pro gig situations outside of the NHs . They never really caught on big in the first place.