Prime Based Kit?

I think there is no standard. It's all about personal preference and shooting type you want.

For me, i currently have 35mm L, 135mm L, 200mm L. I know 200mm L is kind of not too far away from 135, but it's so good that i can keep it. I will part it soon since i just got 70-20mm L II.

I only use zoom during shooting with events or in the environment that won't allow me to me around much. In that case, 28-70mm L and 70-200mm L II  are used.