Sounds complicated..
Not always, but sometimes. (Normal starts - just press the start button, then wait/monitor.)
A high-residual temp, generator assisted start goes as follows:
1. Hold 'starter test' switch (with left hand) on to motor engine
2. At 15% RPM, press 'start' button (with right hand) only until lightoff occurs
3. Release starter test switch, guard stop and feather control (with right hand)
4. Reset-on the generator on the (already running) other engine (with left hand)
5. Guard stop button (with left hand) and monitor that the start computer does it's job.
One got quite good at doing this due to doing it 4-6 times a day on the bank runs
Have since heard some people say that the generator assisted start was only really required on the earlier MIIIs due to reducing the risk of shearing the drive shaft of the operating gen, but that this wasn't a problem on later IIIs and 23s. Never have found a well documented answer for this though.
grade-3