I spend over 30 hours a week doing film scores. Lots of times, I'll do a rough on an arranger and send it to the client or film producer.
Sometimes, I'll take the arranger to the production company, and we'll work with the writer, editor, producer or a combination to come up with the rough.
Occasionally, on very low budget spots for non-profits, I'll actually use something from the arranger. This is not because there is anything wrong with what can be done on an arranger, but rather a preference to keep in the high budget, real player realm. Many times, I could make lots more dollars just using the arranger. That's not what I'm known for. My clients are 2 automobile manufacturers, a national pizza firm and another restaurant chain.
The arranger is responsible for a considerable portion of my music income.
Russ