It's really difficult to achieve this effect.
I used two different shapes to test using them as Art Brushes.
I applied the first one and I use the Widht tool to make the endpoints smaller.
The second I used it as it is.
Some tweaking to the spiral shapes were necessary.
Unfortunately, I could not make the lines interact making them fluid as you can see.
A tricky case as the already existing answer says!
This answer unfortunately must be considered as an oversized comment because it is based on extra tools and the question was about how to make it in Illustrator.
To see how the surface division to squares actually should be drawn in 2D I made a 3D piece in Moi3D, which is a low cost cousin of Rhinoceros. ...
I don't think you can toggle the visibility of margins and columns separately. Either both are on, or both of them are off.
One workaround is to manually add the column lines by drawing the lines on a Master Page on a new layer. When you go back to your pages, you can then toggle the visibility of that column layer.
Every page with this Master Page applied ...
Looks like a math problem indeed.
Not sure why do you need the horizontal so-called 'rows'. The baseline grid looks correct, but the horizontal lines don't make sense. Those have nothing to do with the baseline grid and the way text will flow into your columns.
Also, not sure you're aware you're dealing with 2 units of measurement, MM for the layout and PT ...
InDesign has a proper baseline grid feature and that works as shown in your first image. Actually i think the first image itself is a screenshot from InDesign.
For this and a number of other reasons, Illustrator should not be your first option when designing brochures. Illustrator, as the name implies, was built for illustration, drawings, icons, logos, etc ...
For those who are still wondering, here's an Isometric Grid Template I made with the grid overlaying an artwork layer.
You are free to download and use as desired.
I made a bunch of triangles laid out, then applied a thin dashed stroke at a lower opacity on a locked layer above the artwork.
With photoshop open and a document displayed the size paper you want, go to your snipping tool (not Photoshop, program that comes with Windows I think). Draw around the document, click copy and then in PS on a new layer hit paste. Take off "view grid"