> Today you have to do a whole lot to markdown submit to your toolchain

The brunt of transcoding from Markdown to AsciiDoc can be accomplished in a single line, something like:

    find . -type f -name '*.md' -exec pandoc -f markdown -t asciidoc {} \;

AsciiDoc is a superset of Markdown, so pandoc should be able to do a nearly flawless job at converting:

https://asciidoctor.org/docs/asciidoc-vs-markdown/

At that point it's a matter of updating a few build scripts to pass AsciiDoc files to pandoc instead of Markdown. I wouldn't say starting with AsciiDoc would have been better or worse, just different. Starting with Microsoft Word would have been worse.