That's not the point - grammar doesn't have an underlying truth so there's no reason why one order is right and another isn't. The point is to give an example of how people are able to make progress in successfully using and understanding English without having any awareness of one underlying rule (people will even argue - as they do here in these comments - that there is no underlying rule, even though there certainly does seem to be, even though native speakers are generally never taught it).

That does make it different from mathematics, where there are reasons for the rules (you can't divide both sides of an equation by a value if that value might be zero, for example). But the point is more to suggest that it could be possible to make progress in carrying out and understanding mathematics without understanding some of the formal underlying rules beneath a concept. That seems like a valid point.