I like to follow my own convention where I name files with shell scripts with an extension: .sh for POSIX-compatible scripts, .bash for scripts with bashisms or .zsh for scripts with zshisms.

If I ever wanted to achieve what you initially wanted to achieve - I could use something like

alias -s sh=sh

alias -s bash=bash

alias -s zsh=zsh

Just like I do bind .txt and .conf to 'less', .pdf to 'qpdf', .json to 'ijq', video formats to 'mpv' and so on.