3-The only reason that people hire an arranger player is because of DOLLARS, the do not want to pay for five or six musicians.
There are some exceptions.

I'm lucky to have this gig tomorrow. In their own community this group dances to a free DJ. He was all over me at the last job asking how I did this or that. I told him and doubt if he'll follow up on any of it. I got called last minute to fill in for someone ( who does a Kareoke Rat Pack act ) who cancelled and they were there to see him. Worked out to be a great night so I'm back.
Donny has said it "it don'tmatter how you put it out as long as they like it "