Maybe try the "Numbered Headings" plugin, see
https://www.dokuwiki.org/plugin:numberedheadings. But it requires a slightly different syntax.
Instead of
====== Headline ======
you would need to write
====== - Headline ======
to get a numbered heading.
Positive: does not affect the standard syntax.
Negative: requires extra work to do it and requires extra work if you decide to not use it anymore.