Personally I would skip the nutritional yeast completely. It's only used because it is a very cheap filler.
You could start out mixing the rest in equal proportions. Or you could go to a website like iherb.com and check out the labels from other green powders to get a sense of proportion.
Most companies that make top quality green powders clearly state the exact amounts of each ingrediant used. But Dr Schultz is deceptive with his "...in a base of nutritional yeast" labeling.