In the case of NPM (don’t know enough about the others) it’s not a general purpose package manager, it’s only for node related packages.
And yes I think ranking them is relevant Appimages are pretty terrible security wise(let’s download random executables on the internet yayyy!), snaps are getting better but used to be really terrible and to be fair NixPkgs aren’t that safe either.
Flatpaks are pretty secure, they work well, the stack is fully open source and allows you to host your own flatpaks repos, as well as manage sandboxing parameters. If only they were lighter I could easily see them become the “Linux executable format”