This gets curiouser and curiouser. From what I see quickly on their respective web pages, Puppy and Alpine are both focused on being small and lightweight, and I guess could be seen as somewhat competitive with each other (though, again, this is only based on a cursory look at their respective web sites).
Ubuntu has both server and desktop versions, but the desktop is the more popular by a long shot. Ubuntu Desktop and PC-BSD are both GUI-based desktop OSs, so I guess they could be seen as competing with each other, though of course PC-BSD isn't Linux (it's FreeBSD).
SME Server is the odd one out in this group--it's a text-based server OS with a web-based configuration manager. There is no plausible use case for which all five of these OSs would be considered (somewhat interestingly, though you exclude pfSense in your post, it does overlap somewhat with SME Server in its features). If you've used all five of these, as you say you have, you'd know this. But, of course, I don't know where else you might have posted the same question (though I can now add Tiny Core Linux, Mageia, and Damn Small Linux to the list).
If, as you say, you are trying to "find the best distro for the task that I am trying to do", a much better question to post would be, "I'm trying to do $TASK, with $REQUIREMENTS and $LIMITATIONS. Would $DISTRO be a good choice for this job?" If you post that to forums for distros that have some connection to $TASK, you'll probably get some helpful responses. Your question ("tell me what $DISTRO is good at") is much more likely to get an answer of "RTFM," or some variation. And when you say you've already used $DISTRO, we assume you should already have some idea of what it's good at.
So, what's really going on? My best guess is a school project, but I'm sure I could be wrong on that. All I know is that you've spammed at least eight different forums with the same question, and not given any indication of what you're actually trying to do.