i would imagine that this is why it says---read all instructions first-before beginning- so you know the whole process- and can simplify the technique if you know a different way-
i've done lots of Carol Doak patterns and have never run into this situation- is it an (older) book? where things have changed with time?
as for being 'normal' maybe it was the normal way when she wrote the book. but when ever trying out a new pattern it really helps to read the whole thing-start to finish before cutting a single piece of fabric....sometimes there are errors (no one's really perfect-including proof-readers) and if you read through the pattern first sometimes you can see the errors before you make incorrect cuts