What do you really need to know beyond pull, push, commit, stash, rebase, worktree, and .gitattributes?
But it's not really about the number of subcommands, but rather how complex some of these subcommands are. e.g. git-commit(1) is 655 lines (and references other pages, too). hg's "help commit" is 59 lines, or 98 with --verbose (this also references some other pages, so it's not all you need, but it's indicative of the relative complexity).
> Multiple checkout in general is still experimental, and the support for submodules is incomplete. It is NOT recommended to make multiple checkouts of a superproject.
I'm not quite sure what is safe and what is risky.