I think NB can work on it's own really, and everyone is different, there are fast responders and slow responders. No one can really say for sure if something is the cause of their growth because it just could be the NB alone. I have a high protein diet because I also take BO. Is it responsible for my growth? Probably, but I can't prove it. And you are asking for something that no one can answer. Some people grow with just taking fenugreek while others don't. All you can do is try, if it's not working for you then after a while stop. I've done plenty of various things for NBE the past 4 years, there were things I took that didn't work. Like some say soy milk helps, I tried it for a couple months and no difference, so I stopped it and went back to regular milk. It wasn't a big deal to me. So like I said you want to try it, go for it see how it works for you, if not then don't. I think NB can work just fine on it's own but for the slower responders they try to experiment with different things to help the NB process along. It's all experimentation. And I wasn't trying to jump on you, it's just some don't see results they want with NB right away and they tend to go a bit overboard trying to find that miracle thing, when in reality there is no miracle, NBE takes time and commitment. And I'm glad you are seeing results with NB. But yea, actually a doctor will tell you a high protein diet is good for maintaining a healthy weight and lean muscles. So really you can't lose with at least trying. You don't have to drink protein shakes, you can just eat protein rich foods. I normally get 80g or more in protein from my diet alone, it's only very seldom I don't and that's when I have a shake or a bar. I get non-flavored whey protein isolate and I put it in chocolate or strawberry milk, I put it in smoothies, I mix it in soups, etc. It's very versatile and can be used in most anything.
From my experience if I don't get 80 to 90 something grams of protein per day, I don't get as much growth signs, tingles, soreness, itches, etc. and I don't grow as much in that month. But again, I take BO and BO works on a high protein diet, it feeds off the protein to create breast growth. So that could very well be that I take BO, I can't say it works alone with NB. But you can always try it, and let the others know if it worked for you without taking BO.
But this is the same with water intake. I notice if I don't drink enough water throughout the day that night when I pump I only get 1/4 inch of swelling. But if I drink 2 liters of water throughout the day (about 64 oz) then I get anywhere from 1 inch to 1 1/2 inches of swelling. So I think for NB water is key. And no I can't prove or guarantee it works, I just know that's from my own experience. But I drink water for general health anyway. It helps with my acne, my hair, etc.
In whatever you decide to try or not try, I wish you the best and hope you get the results you're looking for!