Unequal, on one axis
The tracks are a geometric run: each one is the last divided by a single ratio. Nothing here is halved and nothing is centred, and what holds it together is that almost everything begins on the same line.
Ratio 1.38, four tracks, axis on two
The axis is the point
A page like this works because a great many things start at the same x, and the eye finds that line and holds on to it. Take the axis away and unequal columns are not a composition, they are a mess.
The narrow column is for the small voice
The run is widest first, so the narrow tracks fall exactly where captions, notes and numbers want to be. Body copy in the narrowest track is the system used backwards, and the giveaway is a column of two-word lines.
A note, where a note goes.
Three plates, three different widths, one top line
One ratio, applied once
Pick the widths by eye, section by section, and you do not have a grid. You have a series of decisions that happen to be unequal, and a reader feels the difference even if they could not name it.
Across every track. The margin is still there, so this bleeds to the grid rather than to the window.