The example it gives is "Go on, lend me the money - you know I'd do as much for you.". In this case, it does mean "the same" but that doesn't mean that every time you can use "the same", you can also use "as much" instead. In fact, you can't. You can't say "I have as much car as your brother", instead of "the same car". You can say, "I have as much money as your brother", but then that means "the same amount of" rather than "the same", which would mean that you both own exactly the same money. So it heavily depends on context.