First-time customers sometimes lose their way during the installation process.

An overview section at the beginning of the Installation guides, with links to the relevant sections, would help a new user to understand what they have to do next.

I recommend following the TOC structure. Each section should have a brief summary (what job is the user doing, what is the result) and a link to the relevant section.

Note: this section will require maintenance, although not as much as when linking to external docs. If a section is removed or the anchor ID changes, the doc will not build and the problem can be fixed immediately. However, new sections will have to be added manually. Probably the only solution is to ensure that writers are aware of this overview.