Since a competent typist could type that in at most 3 seconds, it's worth a shot.

It should, as long as you don't try to abbreviate it as tar -h though... the short form is tar -? which illustrates the joke nicely

Is

man tar

a Tar command or a Man command?

I'd use tar -help and we'd all die

Probably not, the double-dash long commandline option is a GNU extension and isn't guaranteed to work with every tar implementation.