The answer to the question "Should I make this post Community Wiki" is nearly always going to be "No".
No answer must be community wiki
The Community Wiki feature is a tool to encourage collaboration; it is not a mandate, and there is nothing either in the community-at-large or in the SE system saying "This Shalt Be CW"1.
Much of the guidance for when answers could be made CW is outlined in these two blog posts by GraceNote, one of our Community Managers. The only time you should be considering making a post CW is when it would benefit from collaboration from the community.
Practically speaking, some of the times that comes up for us are:
That last bullet point raises a good point, which I want to expand on:
Just because an answer could be CW doesn't mean it should be CW
The point of marking a post CW is to encourage collaboration; it lowers the reputation requirement for editing, and removes the reputation incentive (i.e. personal ego) attached to the post. There are perhaps many situations where this could be beneficial, but virtually none where it's necessary.
Any question that could be CW can also survive quite well as a non-CW answer. Valorum's answer above is a good example; another is What novels or movies are set in these fantasy lands?, which has both a CW and a non-CW answer; or my answer to How many non-Doctor regenerations have we seen on-screen?, which has seen collaboration in the comments helping me with things I'd forgotten.
The problem, which GraceNote points out in that first blog post I linked to is that we already have collaboration through more edits, thanks to the Suggested Edit feature. To crib from him:
[E]ven in answers, true collaboration is scarce. Most of the time, a single individual can provide a complete answer. There are even times where a question looks like it'll need a massive effort, but one gallant user steps up to the plate with an impressive and comprehensive answer.
Most of the time, you should be asking yourself "How can I improve this post so that community wiki isn't needed?" Community wiki is like a cheese knife: it is a specialized tool to be used sparingly.
Community wiki is for that rare gem of a post that needs true community collaboration.
Your specific answer
The answer you linked to in the question would not, in my opinion, benefit from being made CW. Why?
- It's a complete answer to the question. Insofar as any answer to a question about a 80-year-old franchise can be considered "complete", that one is; it provides an example of the current state of affairs, which is also the current state of canon
Any additions would be quite minor. Why do you think your answer would benefit from collaboration? The one thing it lacks is a perspective on the history of the Superman canon, which is largely unnecessary except for historical interest. There's a reason DC occasionally reboots their universe, and personally I don't see an excessive amount of value being gained from discussing the differences between modern Superman and Golden Age Superman. That's not to say the value doesn't exist, but the marginal benefit isn't enough to justify making the answer CW.
Perhaps there's an argument that your answer is incomplete, because perhaps there are other examples in the current canon contradicting your statements. Maybe that's true - I don't know - but it still doesn't mean you should make the answer CW. Long history has shown that, if your answer is incomplete, someone will either leave a comment telling you, or else post a better answer themselves. That's the way the site is designed to work; if we marked every incomplete answer as CW, we'd have to make every answer as CW, which isn't the kind of community this is.
1 This wasn't always the case, of course; until 2014, answers that satisfied certain conditions would be automagically converted into CW answers. This is, thankfully, no longer the case.