Protein Blends

I’ve been reviewing different protein powders and have noticed that many claim they are utilizing a blend of fast and slow digesting proteins to cover immediately after the workout, up until many hours after consumption.

Does it not make sense that mixing hydrolysate and micellar casein would alter the digestion of a protein powder such that micellar casein slows the digestion of hydrolysate?

My question is, is this a marketing gimmick or is their science to support providing a blend of proteins as opposed to one sole source of protein before, during and after that is versatile like peptopro (MAG-10’s protein source)?