My brothers a dairy farmer in NZ and uses this.

Nz farmers will milk twice a day, early morning and afternoon. In the middle of the day the cows return to their paddock from the morning. In the evening they’re moved to a new paddock.

Grass consumption is the aim of the game. If you let cows out on a full paddock for the day they’ll partially graze and then starve themselves (relatively speaking) in the afternoon.

This is bad for milk production and also pasture quality for the next rotation.

The solution to this is to set a break, a temporary electric fence in the middle of the paddock. So, they arrive to half a paddock then in the morning the farm worker takes it down for the afternoon and sets it up in the next paddock for the night. Probably takes 30-45 minutes depending on paddock size, weather and enthusiasm of the farm hand.

x2 for 2 herds, 7 days a week for 8 months a year.

Now, my brother just draws a line on a map and it takes care of itself.

That could be the big difference. Our herd was for beef which is definitely a lot more hands off vs dairy farming.