Fink, Homebrew, MacPorts, pkgsrc — can I run them in parallel on the same machine?

I've been using Homebrew on my Mac forever, but sometimes I run into situations where a package is not available. For maximum choice, which of the 4 major package managers (am I missing any?) can be installed alongside each other, without undefined behavior? I assume it gets ugly unless one picks a primary package manager, and then just uses other ones for very targeted, narrow installs that don't duplicate dependencies etc.