Yogurt has less sugar than non-cultured milk, as the bacteria in the yogurt metabolize much of the lactose. It still has some, but notably less than regular milk. And, it also provides beneficial (probiotic) bacteria that are worthwhile to the fight against candida. Regular milk does not.
I suspect the recipe(s) that say chickpeas in Stage 1 are a mistake. Chickpeas are specifically listed among the “foods to reintroduce” in Stage 2: http://www.thecandidadiet.com/foods-to-reintroduce.htm
But I also Googled soba noodles, and read that they are made from buckwheat which is non-glutinous and on the “foods to eat” list for Stage 1.
I hope this helps!