I believe he makes a lot of valid points. I'm not too into the 900 pound cow though, 12-1300 seems to be where my best ones wind up at. There are exceptions, had a little 850 lb shorthorn that would wean a calf that weighed within 50lb of the group, and she was rarely at the hay ring, usually out picking instead. If they were all like her, maybe, but most of my dink cows have raised dink calves.
I know for a fact there's something to giving grass rest. Not many people have the time to move them 1-3 times a day, I sure don't. All my pastures are small and require hauling, so I can't make full use of them as well as I'd like without buying more bulls and keeping smaller groups, but I've seen good benefit from putting cows on cornstalks in the winter and letting pastures rest from constant picking and foot traffic. I don't like to see them in to mud up to their brisket, so a small sacrifice lot is out for me. Feeding in GoBob monsters now, and move the feeders every time, but building an unroller is in the plans. I'm also with Greg, buy nutrients (hay) and haul them into your farm. Can buy it as cheap as raise it, get feed and build soil at the same time for the same money.