i was a personal trainer for many years and knew/know lots of bodybuilders and power-lifters. they are LAST people on earth i take nutritional advice from and i was anorexic back then!
your thinking you need casein to lift seems to contradict what you wrote upthread about not wanting big muscles, just strong ones? you can get more complete protein from muscle meats and organs, sorry.
As I ate the oysters with their strong taste of the sea and their faint metallic taste that the cold white wine washed away, leaving only the sea taste and the succulent texture, and as I drank their cold liquid from each shell and washed it down with the crisp taste of the wine, I lost the empty feeling and began to be happy and to make plans.
– Ernest Hemingway