Stick with me, this might get complicated. I'm a crew neck gal.
The pattern has you start with the neckline ribbing, then increase to the stitch count needed for the stranded work.
Instead of putting it on scrap yarn, grab an extra circ, with as long a cable as you have, set it up with needles a size smaller than your working needles, and slip half of your stitches onto it, leaving the other half on your working needles. You can easily try it on like that.
I da a provisional cast on of the number of stitches I would need for the chart, skipping the neckline ribbing and subsequent increases.
When I was ready for the neckline, I picked up these stitches and sort of, reversed the beginning of the pattern, decreasing evenly around the neck about 30% of the stitches.
Then I did some short rows to build up the back neck, about an inch. I didn't do any special spacing or wrap and turns. I literally sectioned off the "back" of the sweater, and knit flat for one inch. I rejoined everything, and it makes the back neck an inch taller.
I did almost raglan decreases for few rounds, and then 7 rounds for the rolled collar, and bound off with k2tbl, slip st back on left needle.
There was a lot of pausing and putting it all on scrap yarn and trying it on to get the fit just right.
When you're working circularly (this won't work if you're in a short row section or otherwise working flat), with an interchangeable set, put the correct needle tip on one end and a size or two smaller on the other end. Do the same with a spare cable. Now you can knit the stitches onto the extra circ instead of just slipping them.
And setting circs up with smaller needle on the side you're knitting off of can speed up your knitting because the stitches will glide off of the smaller needle more easily.