Is there really a benefit in building this levain?

Is there really a benefit in building this levain?

I’m in the process of building a new rye starter to make a 75% rye Baurenbrot and the beginning of the recipe has me thinking that it might be redundant so I wanted to get some thoughts from the experts.

 

It has you mix 200g rye flour and 200g water with 50g of Anstellgut, let it sit for 16 hours, reserve 50g for future starters, and then mix it with the rest of the ingredients.

Why wouldn’t I just pull 400g of Anstellgut out?  Or is the recipe just assuming I don’t have this quantity from the start?

Source: Fresh Loaf