I equally understand your analysis, and players won't be thinking about it, I believe. Only we on here have the leisure to do that.
I don't think it's only about the final goal difference consideration. The plain fact is that if you've got a 3-0 cushion, or more, round about the sixty-minute mark, you can start sending subs on, and giving your key players valuable rest, while keeping your subs sharp. In a schedule as crowded as ours in the coming month that may well be important. If you're only leading 1-0 managers are notoriously wary of mixing it up, unless obliged to by injury. And Pep's no different there.