Robert
It was not long ago that these pages did not exist.
The methods described work.
We are in transition. Using 3.6 you can install tinycore one way. Yet install.gz and grub4dos.gz have been released, creating other options. People installing 3.7 need the new options. The aim is to make it as simple as possible, yet cover both options, which makes it more confusing.
These pages have not been updated since the release of the multicore.iso. That is another option to add.
Once we have passed the major changes, installation guides should get simpler.
For a long time, a lot of the tinycore documentation was several versions behind. There are probably some pages still based on older versions.
When a new version is released, there may not be time to update the documentation immediately. There are several pages which need updating.
One of the reasons for including 3.7 options, is so that when the 3.7 final is released, there is already documentation covering it.