anal from analytical I hope?
ok. this is my last post here as I seem to be wasting my time.
when you take a look at images A and B on that tutorial, you will notice that the squares in A have become rectangles in B.
proof: the height of the first row in B is larger than in A while, due to foreshortening, it should be smaller (less).
To get squares in perspective you have one and only one exact relation between height and width. You can not get this by simply making that square grid shorter the way you fancy.
This tutorial is not serving its purpose. And giving half-hearted solutions is not the purpose of QT&T forum.