Ah, but then if ẟ is not a single number, that brings down the whole concept of ‘Zigzagging’, right?–As the weight vectors are actually not changing together in ‘fixed directions’. Their directions are unique as ẟ is a vector. But then, can you give me a pointer to an article or a paper which explains why normalizing is necessary without using this ‘Zigzagging’ reference  as most of what i have come across uses this. Thanks