oxi:
You're exactly right.
But the number of times people have tried to take off with one engine at idle and one at flight in all the helicopters with the P&W 206/207 (except the Bell 427/429- more on that in a minute) is amazing.
You would think that a quick check of the gauges would be in order prior to lifting the collective, but it appears as though there are a lot of folks who don't.
The Bell 427/429 did not go with three-position switches - they have a two-position switch - off and start. The engines are taken from idle to fly using the collective mounted throttles. Bell also declares an engine failure on the basis of a torque split instead of on compressor speed on those two machines.