> The version number should never appear in the command name.

Well, that's nice in theory, but...

> In 50+ years of typing into terminals, we have not figured out how to have multiple versions of things coexist peacefully.

Well, yes, we have. By making the version number appear in the command name. It's not a great solution, but it's a solution. And since you didn't really provide a better one, it's pretty silly to advice against using it.

Also, symlinks are a thing. Nobody (normally) invokes python3.7m directly. There's a symlink pointing to it (or more likely not, as it's probably not the python you want).