When we combine things we try to take multiple things and by bringing them together we intend to make the whole greater then the sum of their parts.
Changing one thing might seem to be a minor change but might result in a dramatically different end product. This is true whether the change is an add or subtraction.
As an example, as we all know water is the combination of two parts hydrogen and one part oxygen. If we want “better water” we might think “well if one part oxygen makes good water, maybe two parts of oxygen added to two parts hydrogen will make better water!” The reality is that adding that additional part of oxygen will change the final product from water to hydrogen peroxide. While hydrogen peroxide has many uses, it’s not a form of “better water”.
The same applies with food. Making one change to a recipe might make a major change to the final product. A couple of years ago I went to a restaurant I had never been to and ordered something from the restaurant but I asked for a minor change to make it “better”. The server suggested I keep the dish as they recommended and give it a try and if I didn’t like it, she would replace it with my preference. Luckily I took her suggestion and the meal was amazing. The server knew that their combination simply worked and altering it even slightly would have a major effect on the final dish.
There are times when certain combinations should be changed (in the case of food, it might be because of allergies) but for the most part we should trust the original combination, unless it’s proven to not work.
Have a great day!