I totally quoted the wrong section of that Codex page. Here's the relevant text, that immediately follows what I quoted above:
If the creation of a top-level menu is not necessary, decide under what top-level menu to place your sub-level menu item. As a point of reference, most plugins add sub-level menu items underneath existing WordPress top-level menus. For example, the Backup plugin adds a sub-level menu option to the Tools top-level menu. Please note with the taxonomy registration, WordPress automatically creates sub-level menus under the applicable top-level menu to manage those features.

Use this guide of the WordPress top-level menus to determine the correct location for your sub-level menu item:

Dashboard
Information central for your site and include the Updates option for updating WordPress core, plugins, and themes.
Posts
Displays tools for writing posts (time oriented content).
Media
Uploading and managing your pictures, videos, and audio.
Links
Manage references to other blogs and sites of interest.
Pages
Displays tools for writing your static content called pages.
Comments
Controlling and regulation reader to responses to posts.
Appearance
Displays controls for manipulation of theme/style files, sidebars, etc.
Plugins
Displays controls dealing with plugin management, not configuration options for a plugin itself.
Users
Displays controls for user management.
Tools
Manage the export, import, and even backup of blog data.
Settings
Displays plugin options that only administrators should view (also see Creating Settings Pages).

Note what it says about the Plugins menu, specifically:
Plugins
Displays controls dealing with plugin management, not configuration options for a plugin itself.

I don't think Akismet has anything to do with "Plugin management".