Cups and servings? why not exact amounts ?

I am getting to the end of the first week and one thing that bugs me is that some measurements are accurate, yet others are so vague.

For instance, we are often told a ‘Serving of veg of your choice.. OK, so what is that? 10 grams, 100 grams? 500 grams?

Last night one of the even meal items was Roasted Egg plant (Aubergine in British english)
The amount says a rather vague ” Cupful “.

I’ve gone through my cupboard and a cupful of water can weigh any where from about 100grams to 450 grams depending on the size of cup you choose. o 100 -450 ml

I like to have accuracy in my measurements.

Any chance you can lose these vague terms in the menu planner and put proper measured amounts.

Last night, even using a smaller cup size, I had too much.
The menu planner came up with

130gram Tuna
three quarters a cup of green peas
½ cup lentils
1 cup of egg plant.

Well that amount, even using a mid sized cup, fed both myself and my partner.